chronic beryllium disease

Chronic beryllium disease (CBD) is a granulomatous, interstitial lung disease that occurs in individuals who develop beryllium sensitization (BeS), a cell-mediated immune response to environmental and occupational beryllium exposure. BeS precedes the lung disease that may present with chronic dry cough, fatigue, weight loss, chest pain, and increasing dyspnea.


medullary thyroid gland carcinoma

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A neuroendocrine carcinoma arising from the C-cells of the thyroid gland. It is closely associated with multiple endocrine neoplasia syndromes. Approximately 10% to 20% of medullary thyroid carcinomas are familial. Patients usually present with a thyroid nodule that is painless and firm. In the majority of cases nodal involvement is present at diagnosis. Surgery is the preferred treatment for both primary lesions and recurrences. This carcinoma is generally not very sensitive to radiation and almost unresponsive to chemotherapy.


familial pancreatic carcinoma

Familial pancreatic carcinoma is defined by the presence of pancreatic cancer (PC) in two or more first-degree relatives.


chronic mucocutaneous candidiasis

Mucocutaneous candidiasis that is persistent or long-standing in nature.


Carney complex

Carney complex (CNC) is characterized by spotty skin pigmentation, endocrine overactivity and myxomas.


congenital disorder of glycosylation

Congenital disorder of glycosylation (CDG) is a fast growing group of inborn errors of metabolism characterized by defective activity of enzymes that participate in glycosylation (modification of proteins and other macromolecules by adding and processing of oligosaccharide side chains). CDG is comprised of phenotypically diverse disorders affecting multiple systems including the central nervous system, muscle function, immunity, endocrine system, and coagulation. The numerous entities in this group are subdivided, based on the synthetic pathway affected, into disorder of protein N-glycosylation, disorder of protein O-glycosylation, disorder of multiple glycosylation, and disorder of glycosphingolipid and glycosylphosphatidylinositol anchor glycosylation.


herpes simplex virus keratitis

A superficial, epithelial Herpesvirus hominis infection of the cornea, characterized by the presence of small vesicles which may break down and coalesce to form dendritic ulcers (keratitis, dendritic). (Dictionary of Visual Science, 3d ed)


neurotrophic keratopathy

Neurotrophic keratopathy is a rare degenerative disease of the cornea characterized by reduction or loss of corneal sensitivity that can be asymptomatic or present with red-eye and, during the early stages of the disease, a minor decrease in visual acuity. It eventually leads to loss of vision.


endotheliitis

An inflammatory disease involving a pathogenic inflammatory response in the endothelium.


nephrogenic systemic fibrosis

Nephrogenic systemic fibrosis (NSF) is a rare systemic fibrosing condition observed in renally impaired patients and characterized by a hardening and thickening of the skin with fibrotic plaques or papules, pruritus, joint pain and stiffness, muscle weakness, limitation of range of motion, and yellowed eyes. It is generally associated with administration of gadolinium-based magnetic resonance imaging contrast agents (GBCA) in patients with kidney disease.


Asherman syndrome

Adhesions or scar tissue that form inside the cavity of the uterus.


arachnoiditis

Arachnoiditis (ARC) is a chronic inflammation of the arachnoid layer of the meninges, of which adhesive arachnoiditis is the most severe form, characterized by debilitating, intractable neurogenic back and limb pain and a range of other neurological problems.


adrenomyeloneuropathy

An adult form of the peroxisomal disease X-linked adrenoleukodystrophy (X-ALD), characterized by spastic paraparesia and often associated with peripheral adrenal insufficiency in males. Both males and females can be affected with AMN.


drug rash with eosinophilia and systemic symptoms

DRESS syndrome (Drug Rash with Eosinophilia and Systemic Symptoms) is a hypersensitivity reaction characterized by a generalized skin rash, fever, eosinophilia, lymphocytosis and visceral involvement (hepatitis, nephritis, pneumonitis, pericarditis and myocarditis) and, in some patients, reactivation of human herpes virus 6.


differentiated thyroid carcinoma

Differentiated thyroid carcinoma (DTC), also known as papillary or follicular thyroid carcinoma, is a slow-growing malignancy usually presenting in adults as an asymptomatic thyroid mass.


univentricular heart

Univentricular heart (UVH) is a severe congenital cardiac malformation characterized by both atria related entirely or almost entirely to one functionally single ventricular chamber. The clinical manifestations include congestive heart failure, failure to thrive, cyanosis, hypoxemia and neurodevelopmental disabilities.


nasopharyngeal carcinoma

A carcinoma arising from the nasopharyngeal epithelium. It includes the following types: keratinizing squamous cell carcinoma, nonkeratinizing carcinoma (differentiated and undifferentiated), basaloid squamous cell carcinoma, and papillary adenocarcinoma.


craniosynostosis

Craniosynostosis is defined as the premature fusion of one or more cranial sutures leading to secondary distortion of skull shape resulting in skull deformities with a variable presentation. Craniosynostosis may occur in an isolated setting or as part of a syndrome.


cryptosporidiosis

Intestinal infection with organisms of the genus Cryptosporidium. It occurs in both animals and humans. Symptoms include severe diarrhea.


cysticercosis

Cysticercosis is a parasitic infectious disease characterized by cyst formation in the target tissue of Taenia solium (tapeworm) parasite larvae ingested via the feces of a human with a tapeworm (human-to-human fecal-oral transmission) leading to variable clinical manifestations in muscle, the brain, spinal cord, and eyes. Infection of muscle tissue is generally asymptomatic. Cyst development in the brain and spinal cord is known as neurocysticercosis (NCC) and may cause seizures and headache. NCC can follow a serious course and may be life-threatening. Severe cases of cysticercosis are treated with albendazole and anti-inflammatory drugs.


keratoconus

A degenerative, structural disorder of the eye, characterized by a cone-shaped protrusion of the cornea. It may lead to visual disturbances.


anti-neutrophil cytoplasmic antibody-associated vasculitis

Group of systemic vasculitis with a strong association with anca. The disorders are characterized by necrotizing inflammation of small and medium size vessels, with little or no immune-complex deposits in vessel walls.


macroglossia

The presence of an excessively large tongue, which may be congenital or may develop as a result of a tumor or edema due to obstruction of lymphatic vessels, or it may occur in association with hyperpituitarism or acromegaly. It also may be associated with malocclusion because of pressure of the tongue on the teeth. (From Jablonski, Dictionary of Dentistry, 1992)


carnitine palmitoyltransferase II deficiency

Carnitine palmitoyltransferase II (CPT II) deficiency is an inherited metabolic disorder that affects mitochondrial oxidation of long chain fatty acids (LCFA). Three forms of CPT II deficiency have been described: a myopathic form, a severe infantile form and a neonatal form.


common variable immunodeficiency

Common variable immunodeficiency (CVID) comprises a heterogeneous group of diseases characterized by a significant hypogammaglobulinemia of unknown cause, failure to produce specific antibodies after immunizations and susceptibility to bacterial infections, predominantly caused by encapsulated bacteria.


epithelioid hemangioendothelioma

A low-grade malignant blood vessel neoplasm. It is characterized by the presence of epithelioid endothelial cells. The neoplastic cells are arranged in cords and nests, which are embedded in a myxoid to hyalinized stroma.


paroxysmal Hemicrania

Paroxysmal hemicrania (PH) is a primary headache disorder characterized by multiple attacks of unilateral pain that occur in association with cranial autonomic symptoms. The hallmarks of this syndrome are the relative shortness of the attacks and the complete response to indomethacin therapy.


trigeminal autonomic cephalalgia

A headache disorder characterized by episodes of unilateral, short lasting pain and associated ipsilateral cranial autonomic symptoms.


juvenile xanthogranuloma

A benign histiocytic tumor that occurs during childhood; it is distinct from Langerhans cell histiocytosis. It is characterized by the presence of lipid-laden, foamy histiocytes and Touton-type giant cells in the dermis. The lesions usually develop during infancy. They consist of cutaneous papules and nodules (most often in the head and neck). It is sometimes associated with deep soft tissues nodules.


hemophagocytic syndrome

Hemophagocytic syndrome (HPS) is a rare immune disease and a potentially life-threatening disorder characterized by cytokine storm and overwhelming inflammation causing fever, hepatosplenomegaly, cytopenia, hypertriglyceridemia, hyperferritinemia, and hemophagocytosis in bone marrow, liver, spleen or lymph nodes. It can be either primary due to a genetic defect (primary hemophagocytic lymphohistiocytosis), or secondary to malignancies, to infections, most commonly with viruses such as Epstein-Barr virus or cytomegalovirus, human immunodeficiency virus, or to autoimmune disorders such as systemic lupus erythematosus or adult-onset Still disease (secondary hemophagocytic lymphohistiocytosis).


An instance of hemophagocytic lymphohistiocytosis that is caused by an inherited genomic modification in an individual.


Hemophagocytic lymphohistiocytosis due to infections, autoimmune disorders, or underlying malignancies. Signs and symptoms include fever, lymphadenopathy, hepatomegaly, splenomegaly, and pancytopenia.


macrophage activation syndrome

A complication of rheumatic disease that is caused by excessive activation and uncontrolled proliferation of T lymphocytes and well-differentiated macrophages. It is characterized by fever, pancytopenia, liver insufficiency, coagulopathy and neurologic symptoms.


Castleman disease

Castleman disease (CD) is a benign lymphoproliferative disorder that may present as a localized or multicentric form. The clinical manifestations are heterogeneous, ranging from asymptomatic discrete lymphadenopathy to recurrent episodes of diffuse lymphadenopathy with severe systemic symptoms.


subacute cutaneous lupus erythematosus

Subacute cutaneous lupus erythematosus (SCLE) is a form of cutaneous lupus erythematosus (CLE) that can present either as a non-scarring, annular photo-distributed dermatosis or psoriasiform plaques. SCLE is associated with anti-Ro/SSA antibodies and can be drug-induced.


chronic cutaneous lupus erythematosus

Chronic cutaneous lupus erythematosus (CCLE) is a form of cutaneous lupus erythematosus (CLE) that includes five different forms: discoid lupus erythematosus (DLE), chilblain lupus, hypertrophic or verrucous lupus erythematosus, lupus erythematosus tumidus, and lupus erythematosus panniculitis.


pustulosis palmaris et plantaris

A chronic inflammatory disorder that generally occurs in adulthood and is characterized by sterile pustules intermingled with scaly erythemas, vesicles and hyperkeratosis occurring at distinct sites on the palms and soles. It is thought to be an autoimmune disorder precipitated by several factors, including local infection, and smoking.


atopic keratoconjunctivitis

Atopic keratoconjunctivitis is a rare and chronic allergic disease of the cornea and conjunctiva occurring in all age groups characterized by severe itching and burning sensation, conjunctival injection, photophobia and edema with serious cases leading to ulceration of the cornea which can result in blindness. It is often associated with atopic dermatitis.


acquired aplastic anemia

An instance of aplastic anemia that is acquired during the lifetime of the individual.


Dent disease

Dent disease is a rare genetic renal tubular disease characterized by manifestations of proximal tubule dysfunction.


dermatitis herpetiformis

Dermatitis herpetiformis (DH) is a chronic autoimmune subepidermal bullous disease characterized by grouped pruritic lesions such as papules, urticarial plaques, erythema, and herpetiform vesiculae, with a predominantly symmetrical distribution on extensor surfaces of the elbows (90%), knees (30%), shoulders, buttocks, sacral region, and face of children and adults. Erosions, excoriations and hyperpigmentation usually follow. DH may also appear as a consequence of gluten intolerance.


Charcot-Marie-Tooth disease

An inherited degenerative disorder involving the peripheral nerves. It is caused by mutations in the genes that are responsible for the production of proteins necessary for the function and structure of the peripheral nerves. It is characterized by muscle atrophy and weakness in the feet, legs, hands, and arms and loss of sensation in the limbs.


photosensitive epilepsy

An epilepsy characterized by seizures triggered by visual stimuli that form patterns in space or time, such as flashing lights.


scleromyxedema

Scleromyxedema is a rare, severe skin disorder. Signs and symptoms include abnormal accumulation of mucin in the skin (mucinosis), causing papular and sclerodermoid bumps; increased production of fibroblasts (connective tissue cells) in the absence of a thyroid disorder; and monoclonal gammopathy (abnormal proteins in the blood). It often involves internal organs and may affect various body systems. The cause of scleromyxedema is not known. There is no standard treatment. Management may involve the use of intravenous immunoglobulin (IVIG), plasmapheresis, thalidomide and corticoids, or more aggressive interventions, such as autologous bone marrow transplantation.


acute myeloid leukemia by FAB classification

Acute myeloid leukemias that do not fulfill the criteria for inclusion in the group of acute myeloid leukemias which have recurrent genetic abnormalities or myelodysplastic changes, or are therapy-related. This category includes entities classified according to the French-American-British classification scheme.


primary peritoneal carcinoma

A rare carcinoma that arises from the peritoneum and resembles the malignant surface epithelial-stromal tumors that arise from the ovary. Serous adenocarcinoma is the most common histologic variant. It affects women almost exclusively. The diagnosis of primary peritoneal carcinoma can be made only if both ovaries are not involved by tumor, or, if the ovaries are involved, the tumor is confined to the ovarian surface without invasion of the ovarian stroma and the peritoneal involvement is greater than the ovarian surface involvement.


chronic eosinophilic leukemia

A rare myeloproliferative neoplasm characterized by a clonal proliferation of eosinophilic precursors resulting in persistently increased numbers of eosinophils in the blood, marrow and peripheral tissues.  Since acute eosinophilic leukemia is at best exceedingly rare, the term eosinophilic leukemia is normally used as a synonym for chronic eosinophilic leukemia.  In cases in which it is impossible to prove clonality and there is no increase in blast cells, the diagnosis of "idiopathic hypereosinophilic syndrome" is preferred.  (WHO, 2001)


hypereosinophilic syndrome

Hypereosinophilic syndrome (HES) constitutes a rare and heterogeneous group of disorders, defined as persistent and marked blood eosinophilia and/or tissue eosinophilia associated with a wide range of clinical manifestations reflecting eosinophil-induced tissue/organ damage.


refractory anemia with excess blasts in transformation

Refractory anemia with excess blasts in transformation (RAEB-T) is characterized by dysplastic features of the myeloid and usually erythroid progenitor cells in the bone marrow and an increased number of myeloblasts in the peripheral blood. The peripheral blood blast count ranges from 20% to 30%. RAEB-T used to be a subcategory of myelodysplastic syndromes in the past. Recently, the term has been eliminated from the WHO based classification of myelodysplastic syndromes. The reason is that the percentage of peripheral blood blasts required for the diagnosis of acute myeloid leukemia has been reduced to 20%. The elimination of the RAEB-T term by the WHO experts has created confusion and ongoing arguments. Currently, according to WHO classification, the vast majority of RAEB-T cases are best classified as acute leukemias (acute leukemias with multilineage dysplasia following myelodysplastic syndrome). A minority of cases are part of RAEB-2.


severe hemophilia A

Severe hemophilia A is a form of hemophilia A characterized by a large deficiency of factor VIII leading to frequent spontaneous hemorrhage and abnormal bleeding as a result of minor injuries, or following surgery or tooth extraction.


mild hemophilia A

Mild hemophilia A is a form of hemophilia A characterized by a small deficiency of factor VIII leading to abnormal bleeding as a result of minor injuries, or following surgery or tooth extraction.


periventricular leukomalacia

Periventricular leukomalacia (PVL) is a brain injury disorder characterized by the death of the white matter of the brain due to softening of the brain tissue. It can affect fetuses or newborns, and premature babies are at the greatest risk of the disorder. PVL is caused by a lack of oxygen or blood flow to thearea around the ventricles of the brain, which results in the death of brain tissue. Although babies with PVL generally have no apparent signs or symptoms of the disorder at delivery, they are at risk for motor disorders, cerebral palsy, delayed mental development, coordination problems, and vision and hearing impairments. There is no cure for PVL. Treatment is generally supportive. Prognosis is dependent on the extent of damage to the ventricles.


B-cell non-Hodgkin lymphoma

The most common type of non-Hodgkin lymphoma. It includes the most frequently seen morphologic variants which are: diffuse large B-cell lymphoma, follicular lymphoma, small lymphocytic lymphoma and marginal zone B-cell lymphoma. -- 2003


T-cell non-Hodgkin lymphoma

A non-Hodgkin lymphoma of T-cell lineage. It includes the T lymphoblastic lymphoma and the mature T- and NK-cell lymphomas. -- 2003


progressive familial intrahepatic cholestasis

Progressive familial intrahepatic cholestasis (PFIC) refers to a heterogeneous group of autosomal recessive disorders of childhood that disrupt bile formation and present with cholestasis of hepatocellular origin.


cholera

Cholera is an infectious disease, caused by intestinal infection with Vibrio cholerae, characterized by massive watery diarrhea and severe dehydration that can lead to shock and death if left untreated.


rhizomelic chondrodysplasia punctata

Rhizomelic chondrodysplasia is a form chondrodysplasia punctata, a group of diseases in which the common characteristic is calcifications near joints at birth.


dyskeratosis congenita

Dyskeratosis congenita (DC) is a rare ectodermal dysplasia that often presents with the classic triad of nail dysplasia, skin pigmentary changes, and oral leukoplakia associated with a high risk of bone marrow failure (BMF) and cancer.


central diabetes insipidus

Central diabetes insipidus (CDI) is a hypothalamus-pituitary disease characterized by polyuria and polydipsia due to a vasopressin (AVP) deficiency. It can be inherited or acquired (hereditary CDI and acquired CDI).


acute lung injury

A condition of lung damage that is characterized by bilateral pulmonary infiltrates (pulmonary edema) rich in neutrophils, and in the absence of clinical heart failure. This can represent a spectrum of pulmonary lesions, endothelial and epithelial, due to numerous factors (physical, chemical, or biological).


inflammatory myofibroblastic tumor

A multinodular intermediate fibroblastic neoplasm that arises from soft tissue or viscera, in children and young adults. It is characterized by the presence of spindle-shaped fibroblasts and myofibroblasts, and a chronic inflammatory infiltrate composed of eosinophils, lymphocytes, and plasma cells.


folliculotropic mycosis fungoides

Folliculotropic mycosis fungoides is a rare variant of mycosis fungoides (MF), a form of cutaneous T-cell lymphoma, and is characterized by the presence of folliculotropic infiltrates in patch-plaque lesions usually involving the head and neck area.


mixed germ cell tumor

A malignant germ cell tumor characterized by the presence of at least two different germ cell components. The different germ cell components include choriocarcinoma, embryonal carcinoma, yolk sac tumor, teratoma, and seminoma. It occurs in the ovary, testis, and extragonadal sites including central nervous system and mediastinum.


vaginal carcinoma

A carcinoma arising from the vaginal epithelium. The majority of vaginal carcinomas are squamous cell carcinomas.


growth hormone insensitivity syndrome

Growth hormone insensitivity syndrome (GHIS) is a group of diseases characterized by marked short stature associated with normal or elevated growth hormone (GH) concentrations, which fail to respond to exogenous GH administration. GHIS comprises growth delay due to IGF-1 deficiency, growth delay due to IGF-1 resistance, Laron syndrome, short stature due to STAT5b deficiency and primary acid-labile subunit (ALS) deficiency.


aplastic anemia

Anemia resulting from bone marrow failure (aplastic or hypoplastic bone marrow). The production of erythroblasts and red cells is markedly decreased, and it may be associated with decreased production of granulocytes (granulocytopenia) and platelets (thrombocytopenia) as well. Aplastic anemia may be idiopathic or secondary due to bone marrow damage by toxins, radiation, or immunologic factors.


primary orthostatic hypotension

Primary orthostatic hypotension is a rare type of orthostatic hypotension. It is not a disease per se, but a condition caused by several disorders that affect a specific part of the autonomic nervous system, such as multiple system atrophy, young-onset Parkinson's disease, pure autonomic failure, dopamine beta-hydroxylase deficiency, familial dysautonomia, and pure autonomic failure among others. The autonomic nervous system is the part of the nervous system that regulates certain involuntary body functions such as heart rate, blood pressure, sweating, and bowel and bladder control. Orthostatic hypotension is a form of low blood pressure that happens when standing-up from sitting or lying down. Common symptoms may include dizziness, lightheadedness, generalized weakness, leg buckling, nausea, blurry vision, fatigue, and headaches. Additional symptoms can include chest pain (angina), head and neck pain (often affecting neck and shoulders with a coat hanger distribution), decline in cognitive functioning such as difficulty concentrating, temporary loss of consciousness or “blackout”. Some people with primary orthostatic hypotension may also have high blood pressure when lying down. The treatment depends upon several factors including the specific underlying cause including The treatment depends upon several factors including the specific underlying cause and may include physical counter-maneuvers like lying down, sitting down, squatting clenching buttocks, leg crossing, and support garment and medication.


pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a group of diseases characterized by mean pulmonary artery pressure >20 mmHg and elevated pulmonary arterial resistance leading to right heart failure. PAH is progressive and potentially fatal. PAH may be idiopathic and/ or familial, have overt features of venous/capillary involvement (pulmonary veno-occlusive disease, PVOD/pulmonary capillary hemangiomatosis, PCH), induced by drug or toxin (drug-or toxin-induced PAH), or associated with other diseases like congenital heart disease, connective tissue disease, HIV, schistosomiasis, portal hypertension (PAH associated with other disease).


interstitial lung disease

A diverse group of lung diseases that affect the lung parenchyma. They are characterized by an initial inflammation of pulmonary alveoli that extends to the interstitium and beyond leading to diffuse pulmonary fibrosis. Interstitial lung diseases are classified by their etiology (known or unknown causes), and radiological-pathological features.


pneumoconiosis

An occupational lung disorder caused by inhalation of dust particles. It is characterized by bilateral interstitial lung infiltrates. Representative examples include asbestosis, silicosis, anthracosis, and talc pneumoconiosis.


eosinophilic granulomatosis with polyangiitis

Eosinophilic granulomatosis with polyangiitis (EGPA), previously known as Churg-Strauss syndrome, is a systemic vasculitis of small-to medium vessels, characterized by asthma, transient pulmonary infiltrates, and hypereosinophilia.


inherited ichthyosis

Mendelian disorders of cornification affecting all or most of integument characterized by hyperkeratosis and/or scaling, caused by an inherited modification of the individual's genome.


monogenic diabetes

Diabetes mellitus that is caused by mutations in a single gene.


severe combined immunodeficiency

Severe combined immunodeficiency (SCID) comprises a group of rare monogenic primary immunodeficiency disorders characterized by a lack of functional peripheral T lymphocytes resulting in early-onset severe respiratory infections and failure to thrive. They are classified according to immunological phenotype into SCID with absence of T cells but presence of B cells (T-B+ SCID) or SCID with absence of both (T-B- SCID). Both of these groups include several forms, with or without natural killer (NK) cells.


agammaglobulinemia

A decreased level of serum immunoglobulins. It may be inherited or acquired. It is caused by decreased or inefficient production of immunoglobulins from B cells or by a decrease in the numbers of B cells themselves. Low levels of immunoglobulins will affect the immune system's ability to combat bacterial infection. Supplementation of immunoglobulins is needed to prevent worsening outcomes.


cone-rod dystrophy

Inherited retinal dystrophies that belong to the group of pigmentary retinopathies.


primary pigmented nodular adrenocortical disease

A form of bilateral adrenocortical hyperplasia that is often associated with adrenocorticotrophin hormone (ACTH) independent Cushing syndrome and is characterized by small to normal sized adrenal glands containing multiple small cortical pigmented nodules (less than 1 cm in diameter).


Ehlers-Danlos syndrome, kyphoscoliotic type 1

A form of Ehlers-Danlos syndrome characterized by severe hypotonia and kyphoscoliosis at birth, generalized joint hyperextensibility and ocular globe fragility.


Rasmussen subacute encephalitis

A rare, progressive chronic inflammation of a single cerebral hemisphere that usually affects children. It is characterized by severe seizures, loss of motor skills and speech, hemiparesis, and dementia.


benign neonatal seizures

A rare genetic epilepsy syndrome characterized by the occurrence of afebrile seizures in otherwise healthy newborns with onset in the first few days of life.


erythromelalgia

A rare neurovascular peripheral pain disorder due to the intermittent blockage of the blood vessels, usually in the lower extremities or hands. This causes hyperemia and inflammation at the origin of burning pain and skin redness. The attacks are periodic and are commonly triggered by heat, pressure, mild activity, exertion, insomnia or stress. Erythromelalgia may occur either as a primary or secondary disorder. Primary erythromelalgia is caused by gene mutations. Secondary erythromelalgia can result from small fiber peripheral neuropathy of any cause, essential thrombocytemia, hypercholesterolemia, mushroom or mercury poisoning, and some autoimmune disorders.


esthesioneuroblastoma

A rare malignant neoplasm of the sinonasal cavity, arising from the basal layers of olfactory neuroepithelial cells in the superior nasal vault, which usually occurs in the 5th to 6th decades of life and is characterized clinically by non-specific symptoms such as progressive ipsilateral nasal block, sinusitis, facial pain, intermittent headaches, hyposmia/dysosmia, rhinorrhea and epistaxis as well as proptosis, diplopia and excessive lacrimation due to orbital extension. With early treatment and in the absence of distant metastases, ENB appears to have a good prognosis (compared to other superior nasal malignancies), despite a high rate of cervical metastases.


Evans syndrome

Evans syndrome is a rare chronic hematologic disorder characterized by the simultaneous or sequential association of autoimmune hemolytic anemia (AIHA; a disorder in which auto-antibodies are directed against red blood cells causing anemia of varying degrees of severity) with immune thrombocytopenic purpura (ITP; a coagulation disorder in which auto-antibodies are directed against platelets causing hemorrhagic episodes) and occasionally autoimmune neutropenia, in the absence of a known underlying etiology.


Nelson syndrome

A syndrome that develops following bilateral adrenalectomy for Cushing syndrome. The signs and symptoms result from the presence of an adenocorticotropin-secreting pituitary gland adenoma, and include enlargement of the sella turcica and pressure on the adjacent structures, and skin hyperpigmentation.


cleft lip/palate

Cleft lip and palate is a fissure type embryopathy extending across the upper lip, nasal base, alveolar ridge and the hard and soft palate.


endophthalmitis

An infectious process affecting the internal structures of the eye.


Cowden disease

A genodermatosis characterized by the presence of multiple hamartomas in various tissues and an increased risk for malignancies of the breast, thyroid, endometrium, kidney and colorectum. When CS is accompanied by germline PTEN mutations, it belongs to the PTEN hamartoma tumor syndrome (PHTS) group.


cleft palate

Cleft palate is a fissure type embryopathy that affects the soft and hard palate to varying degrees.


filariasis

A parasitic disease caused by tissue-invasive, vector-borne nematodes which can be found anywhere in the human body and that are transmitted to humans through the bite of an infected mosquito or fly or by consumption of unsafe drinking water and which, depending on the subtype can manifest with lymphedema, dermatitis, subcutaneous edema and eye involvement. The disorder is a major public health problem in many tropical and subtropical countries. Six subtypes have been described in the literature: lymphatic filariasis, onchocerciasis, loiasis, mansonelliasis, dirofilariasis and dracunculiasis caused by Wuchereria bancrofti and filarioidea of the genus Brugia; Onchocerca volvulus; Loa loa; Mansonella; Dirofilaria; and Dracunculus medinensis, respectively. Tropical eosinophilia is considered a frequent manifestation.


borderline epithelial tumor of ovary

A low grade epithelial tumor arising from the ovary. It is characterized by an atypical proliferation of epithelial cells. There is no evidence of stromal invasion.


immune-mediated necrotizing myopathy

Necrotizing autoimmune myopathy (NAM) is a rare form of idiopathic inflammatory myopathy characterized clinically by acute or subacute proximal muscle weakness, and histopathologically by myocyte necrosis and regeneration without significant inflammation.


overlap myositis

Overlap myositis (OM) is a form of idiopathic inflammatory myopathy (IIM) characterized by myositis with at least one clinical and/or autoantibody overlap feature.


myotonic dystrophy

An inherited progressive disorder affecting the muscles. It is characterized by muscle wasting and hypotonia, cataracts, heart conduction defects and endocrinopathies.


eosinophilic gastroenteritis

Eosinophilic gastroenteritis (EGE) is a rare benign gastrointestinal disease characterized by the presence of abnormal and nonspecific gastro-intestinal (GI) manifestations, associated with an eosinophilic infiltration of the GI tract, which can affect several segments and involve several layers within the GI wall.


qualitative or quantitative defects of dysferlin


qualitative or quantitative defects of dystrophin


narcolepsy-cataplexy syndrome

A type of narcolepsy characterized by excessive day-time sleepiness associated with uncontrollable sleep urges and cataplexy (loss of muscle tone often triggered by pleasant emotions).


autosomal dominant cerebellar ataxia type II

An autosomal dominant inherited neurodegenerative disorder caused by mutations in the ATXN7 gene. It is characterized by progressive cerebellar ataxia, including dysarthria and dysphagia, cone-rod and retinal dystrophy, and progressive central visual loss resulting in blindness.


optic pathway glioma

Optic pathway glioma (OPG) is a benign tumor that develop along the optic nerve (chiasm, tracts, and radiations) characterized by impairment or loss of vision and may be accompanied by diencephalic symptoms such as reduced growth and alteration in sleeping patterns. OPG are often linked to neurofibromatosis type 1 (NF1).


cryopyrin-associated periodic syndrome

Cryopyrin associated periodic syndrome (CAPS) defines a group of autoinflammatory diseases, characterized by recurrent episodes of systemic inflammatory attacks in the absence of infection or autoimmune disease. CAPS comprises 3 disorders on a continuum of severity: severe CINCA syndrome, intermediate Muckle-Wells syndrome (MWS) and milder familial cold urticaria (FCAS).


cutis laxa

Cutis laxa (CL) is an inherited or acquired connective tissue disorder characterized by wrinkled, redundant and sagging inelastic skin associated with skeletal and developmental anomalies and, in some cases, with severe systemic involvement. Several different forms of inherited CL have been described, differentiated on the basis of the mode of inheritance and differences in the extent of internal organ involvement, associated anomalies and disease severity.


adult hepatocellular carcinoma

Adult hepatocellular carcinoma is the most common primary liver cancer of adulthood. Derived from well-differentiated hepatocytes, it often develops from chronic liver cirrhosis which is most often due to hepatitis B and C virus or alcohol abuse. Symptoms are hepatic mass, abdominal pain and, in advanced stages, jaundice, cachexia and liver failure.


mal de Debarquement

Mal de debarquement (MdD) is a rare otorhinolaryngological disease characterized by a persistent sensation of motion such as rocking, swaying, tumbling and/or bobbing following a period of exposure to passive movement, usually an ocean cruise or other types of water, train, automobile or air travel and less commonly other movements (like sleeping on a waterbed). Onset may be spontaneous in some patients. Manifestations begin shortly after the stimulus, persist for 6 months to years and may be associated with anxiety, fatigue and impaired cognition. Symptoms are often accentuated when in an enclosed space or when attempting to be motionless (sitting, lying down or standing in a stationary position) and are relieved when in passive motion such as in a moving car, airplane or train.


Guillain-Barre syndrome

A spectrum of rare post-infectious neuropathies that usually occur in otherwise healthy patients. GBS is clinically heterogeneous and encompasses acute inflammatory demyelinating polyradiculoneuropathy (AIDP), acute motor axonal neuropathy (AMAN) and acute motor-sensory axonal neuropathy (AMSAN), Miller-Fisher syndrome (MFS) and some other regional variants.


specific language disorder

A disorder characterized by impairment of verbal communication skills, often resulting from brain damage.


kaposiform hemangioendothelioma

Kaposiform hemangioendothelioma is a very rare, aggressive, vascular tumor manifesting in the neonatal period or in infancy as cutaneous vascular tumors to large infiltrative lesions.


solitary fibrous tumor

Solitary fibrous tumor (SFT) represents a diverse group of ubiquitous rare spindle cell neoplasms that may be benign or malignant and that most frequently arises from the pleura and peritoneum and rarely from other sites such as head and neck, liver and skeletal muscle. SFT may be clinically asymptomatic or may present with enlarging mass, compressive effects depending on the site involved and rarely with paraneoplastic manifestations (osteoarthropathy or hypoglycemia).


cystinosis

Cystinosis is a metabolic disease characterized by an accumulation of cystine inside the lysosomes, causing damage in different organs and tissues, particularly in the kidneys and eyes. Three clinical forms have been described: nephropathic infantile, nephropathic juvenile and ocular.


alternating hemiplegia of childhood

A rare neurodevelopmental disorder characterized by recurrent episodes of hemiplegia and paroxysmal disturbances associated with persistent developmental delay and cognitive impairment.


atypical hemolytic-uremic syndrome

A rare, genetic thrombotic microangiopathy due to dysregulation of the alternative complement pathway and characterized by the triad of hemolytic anemia, thrombocytopenia, and acute renal dysfunction.


carcinosarcoma of the corpus uteri

An aggressive malignant mixed epithelial and mesenchymal tumor that arises from the uterine corpus. It usually affects elderly postmenopausal women and presents with vaginal bleeding. It is characterized by the presence of a malignant epithelial component that is usually glandular and a sarcomatous component.


leiomyosarcoma of the corpus uteri

An aggressive malignant smooth muscle neoplasm, arising from the uterine corpus. It is characterized by a proliferation of neoplastic spindle cells.


autoimmune hepatitis

Hepatitis caused by autoantibodies. Drugs, infections, and toxins may trigger the production of the autoantibodies against the liver parenchyma.


Progressive multifocal leukoencephalopathy (PML) is a neurological disorder that damages the myelin that covers and protects nerves in the white matter of the brain. It is caused by the JC virus (JCV). By age 10, most people have been infected with this virus, but itrarelycauses symptoms unless the immune system becomes severely weakened.The disease occurs, rarely, in organ transplant patients; people undergoing chronic corticosteroid or immunosuppressive therapy; and individuals with cancer, such as Hodgkins disease, lymphoma, and sarcoidosis. PML is most common among individuals with acquired immune deficiency syndrome (AIDS).


neuroendocrine cell hyperplasia of infancy

Neuroendocrine cell hyperplasia of infancy (NCHI) is a non-lethal pediatric form of interstitial lung disease (ILD) characterized by tachypnea without respiratory failure.


diffuse cutaneous systemic sclerosis

Diffuse cutaneous systemic sclerosis (dcSSc) is a subtype of Systemic Sclerosis (SSc) characterized by truncal and acral skin fibrosis with an early and significant incidence of diffuse involvement (interstitial lung disease, oliguric renal failure, diffuse gastrointestinal disease, and myocardial involvement).


limited cutaneous systemic sclerosis

Limited cutaneous systemic sclerosis (lcSSc) is a subtype of systemic sclerosis (SSc) characterized by the association of Raynaud's phenomenon with skin fibrosis limited to the hands, face, feet and forearms.


dermatomyositis

Dermatomyositis (DM) is a type of idiopathic inflammatory myopathy characterized by evocative skin lesions and symmetrical proximal muscle weakness.


glossopharyngeal neuralgia

Glossopharyngeal neuralgia is a condition characterized by repeated episodes of severe pain in the tongue, throat, ear, and tonsils (areas connected to the ninth cranial nerve, or glossopharyngeal nerve). It typically occurs in individuals over age 40. Episodes of pain may last from a few seconds to a few minutes, and usually occur on one side. The pain may be triggered by swallowing, speaking, laughing, chewing or coughing. The condition is thought to be due to irritation of the nerve, although the source of irritation is unclear. The goal of treatment is to control pain, but over-the-counter pain medications are not very effective; the most effective drugs are anti-seizure medications. Some antidepressants help certain people. Surgery to cut or take pressure off of the glossopharyngeal nerve may be needed in severe cases.


nephrogenic diabetes insipidus

Nephrogenic diabetes insipidus (NDI) is characterized by polyuria with polydipsia, recurrent bouts of fever, constipation, and acute hypernatremic dehydration after birth that may cause neurological sequelae. Polyuria may exceed 10 liters in children.


central congenital hypothyroidism

Central or secondary congenital hypothyroidism is a type of permanent congenital hypothyroidism characterized by permanent thyroid hormone deficiency that is present from birth and secondary to a disorder in the thyroid-stimulating hormone (TSH) - thyrotropin-releasing hormone (TRH) system.


fusariosis

Fusariosis describes a superficial, locally invasive, disseminated infection with the pathogenic fungus species, Fusarium, often found in soil and water, which is mainly transmitted to humans through traumatic inoculation and that manifests with keratitis, onychomycosis and less frequently peritonitis and cellulitis. In the immunocompromised, disseminated fusariosis is more common and it manifests with refractory fever, skin lesions (ecthyma-like, target, and multiple subcutaneous nodules), severe myalgias and sino-pulmonary infections.


insulin-resistance syndrome type B

Type B insulin-resistance syndrome belongs to the group of extreme insulin-resistance syndromes (which includes leprechaunism, the lipodystrophies, Rabson-Mendenhall syndrome, and type A insulin resistance syndrome) and occurs in the context of immune dysfunction.


asbestosis

A lung disorder caused by inhalation of asbestos fibers. It results in fibrosis of the lung parenchyma. Signs and symptoms include coughing, shortness of breath and chest pain.


pachyonychia congenita

Pachyonychia congenita (PC) is a rare genodermatosis predominantly featuring painful palmoplantar keratoderma, thickened nails, cysts and whitish oral mucosa.


Usher syndrome type 2

A syndrome characterized by congenital, bilateral sensorineural hearing loss that is mild to moderate in the low frequencies and severe to profound in the higher frequencies, no abnormalities in the vestibular system, and retinitis pigmentosa.


beta-thalassemia major

Beta-thalassemia (BT) major is a severe early-onset form of BT characterized by severe anemia requiring regular red blood cell transfusions.


bronchogenic cyst

Bronchogenic cysts (BCs) are congenital malformations resulting from abnormal budding of the foregut and are most commonly found in the mediastinum.


Lennox-Gastaut syndrome

Lennox-Gastaut syndrome (LGS) belongs to the group of severe childhood epileptic encephalopathies.


lymphoproliferative syndrome

A disorder characterized by proliferation of lymphocytes at various stages of differentiation. Lymphoproliferative disorders can be neoplastic (clonal, as in lymphomas and leukemias) or reactive (polyclonal, as in infectious mononucleosis).


hyperphenylalaninemia due to tetrahydrobiopterin deficiency

Hyperphenylalaninemia (HPA) due to tetrahydrobiopterin (BH4) deficiency, also known as malignant HPA is an amino acid disorder with neonatal onset that is clinically characterized by the classic manifestations of phenylketonuria (PKA) and that later on is clinically differentiated by neurologic symptoms such as microcephaly, intellectual disability, central hypotonia, delayed motor development, peripheral spasticity and seizures, that develop and persist despite an established metabolic control of plasma phenylalanine.


loiasis

Loiasis is a form of filariasis (see this term), caused by the parasitic worm Loa loa, endemic to the forest and savannah regions of Central and Western Africa. Loiasis may either be asymptomatic or manifest as a large, transient area of localized, non-erythematous subcutaneous edema (Calabar swellings), adult worm migration through the sub-conjunctiva (''African eye worm'') and pruritus. Generalized itching, hives, muscle pains, arthralgias, fatigue, and adult worms visibly migrating under the surface of the skin may be observed. Severe complications such as encephalopathy have been reported in highly infected individuals receiving ivermectin during mass drug administration programs for the control of onchocerciasis and lymphatic filariasis.


primary ciliary dyskinesia

A rare, genetically heterogeneous, primarily respiratory disorder characterized by chronic upper and lower respiratory tract disease. Approximately half of PCD patients have an organ laterality defect (situs inversus totalis or situs ambiguus/heterotaxy).


congenital pulmonary airway malformation

An abnormality in lung development that is characterized by a multicystic mass resulting from an adenomatous overgrowth of the terminal bronchioles with a consequent reduction of pulmonary alveoli. This anomaly is classified into three types by the cyst size.


systemic mastocytosis

Systemic mastocytosis (SM) comprises a heterogeneous group of rare acquired and chronic hematological malignancies that are related to an abnormal proliferation of mast cells in tissue, including bone marrow, with or without skin involvement.


arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a heart muscle disease that consists in progressive dystrophy of primarily the right ventricular myocardium with fibro-fatty replacement and ventricular dilation, and that is clinically characterized by ventricular arrhythmias and a risk of sudden cardiac death.


superficial siderosis

Superficial siderosis is a rare neurologic disease characterized by progressive sensorineural hearing loss, cerebellar ataxia, pyramidal signs, and neuroimaging findings revealing hemosiderin deposits in the spinal and cranial leptomeninges and subpial layer. The disease progresses slowly and patients may present with mild cognitive impairment, nystagmus, dysmetria, spasticity, dysdiadochokinesia, dysarthria, hyperreflexia, and Babinski signs. Additional features reported include dementia, urinary incontinence, anosmia, ageusia, and anisocoria.


inhalational anthrax

A rare acute systemic infection caused by the inhalation of Bacillus anthracis spores (e.g. through infected animal products, bioterrorism) and characterized by an initial stage where patients present with non specific symptoms (fever, cough, chills, fatigue) that is followed by an acute phase during which hemorrhagic mediastinitis occurs that can progress into meningitis, gastrointestinal involvement, and refractory shock, that can be fatal, if left untreated.


meningioma

A generally slow growing tumor attached to the dura mater. It is composed of neoplastic meningothelial (arachnoidal) cells. It typically occurs in adults, often women and it has a wide range of histopathological appearances. Of the various subtypes, meningothelial, fibrous and transitional meningiomas are the most common. Most meningiomas are WHO grade I tumors, and some are WHO grade II or III tumors. Most subtypes share a common clinical behavior, although some subtypes are more likely to recur and follow a more aggressive clinical course. (Adapted from WHO)


idiopathic recurrent pericarditis

A rare autoinflammatory syndrome defined as recurrence of pericardial inflammation of unknown origin following the first episode of acute pericarditis and a symptom-free interval of 4-6 weeks or longer. Recurrent attacks of chest pain may be the sole presentation or the chest pain may be accompanied by pericardial friction rub, electrocardiographic or echocardiographic changes, pericardial effusion and increased C-reactive protein. Cardiac tamponade is a rare, life-threatening complication.


sickle cell-beta-thalassemia disease syndrome

Sickle beta thalassemia is an inherited condition that affects hemoglobin, the protein in red blood cells that carries oxygen to different parts of the body.It is a type of sickle cell disease. Affected people have a differentchange (mutation) in each copy of their HBB gene: onethat causes red blood cells to form a 'sickle' or crescent shape and a second that is associated with beta thalassemia, a blood disorder that reduces the production of hemoglobin. Depending on the beta thalassemia mutation, people may have no normal hemoglobin (called sickle beta zero thalassemia) or a reduced amount of normal hemoglobin (called sickle beta plus thalassemia). The presence of sickle-shaped red blood cells, which often breakdown prematurely and can get stuck in blood vessels, combined with the reduction or absence of mature redblood cells leads to the many signs and symptoms of sickle beta thalassemia. Features, which may include anemia (low levels of red blood cells), repeated infections, and frequent episodes of pain, generally develop in early childhood and vary in severity depending on the amount of normal hemoglobin made. Sickle beta thalassemia is inherited in an autosomal recessive manner. Treatment is supportive and depends on the signs and symptoms present in each person.


sickle cell-hemoglobin c disease syndrome

A rare, genetic hemoglobinopathy characterized by anemia, reticulocytosis and erythrocyte abnormalities including target cells, irreversibly sickled cells and crystal-containing cells. Clinical course is similar to sickle cell disease, but less severe and with less complications. Signs and symptoms may include acute episodes of pain, splenic infarction and splenic sequestration crisis, acute chest syndrome, focal segmental glomerulosclerosis, ischemic brain injury, peripheral retinopathy, and osteonecrosis.


high grade astrocytic tumor

An anaplastic astrocytoma (grade III astrocytic tumor) or glioblastoma (grade IV astrocytic tumor).


gliosarcoma

A rare histological variant of glioblastoma (WHO grade IV) characterized by a biphasic tissue pattern with alternating areas displaying glial and mesenchymal differentiation (WHO).


giant cell glioblastoma

A rare histological variant of glioblastoma (WHO grade IV) with a predominance of bizarre, multinucleated giant cells, an occasionally abundant stromal reticulin network, and a high frequency of TP53 mutations. (WHO)


gliomatosis cerebri

A diffuse glial tumor which infiltrates the brain extensively, involving more than two lobes. It is frequently bilateral and often extends to the infratentorial structures, even to the spinal cord. It is probably of astrocytic origin, although GFAP expression may be scant or absent. (Adapted from WHO.)


anaplastic astrocytoma

Anaplastic astrocytoma is a rare, high-grade, malignant glial tumor, histologically characterized by abundance of pleomorphic astrocytes and multiple mitotic figures, often associated with diffuse infiltration of the surrounding tissue, considerable edema and mass effect and involvement of the contralateral brain. Depending on the primary localization of the tumor, patients can present with signs of raised intracranial pressure (headache, vomiting, papilledema), seizures, progressive neurological deficits, and/or behavioral changes. The tumor is most commonly localized in the frontal and temporal lobes, brain stem and spinal cord.


diffuse astrocytoma

A low-grade (WHO grade II) astrocytic neoplasm. It is characterized by diffuse infiltration of neighboring central nervous system structures. These lesions typically affect young adults and have a tendency for progression to anaplastic astrocytoma and glioblastoma. Based on the IDH genes mutation status, diffuse astrocytomas are classified as IDH-mutant, IDH-wildtype, and not otherwise specified.


fibrillary astrocytoma

The most frequent histological variant of diffuse astrocytoma. It is predominantly composed of fibrillary neoplastic astrocytes. Nuclear atypia is a diagnostic criterion but mitotic activity, necrosis and microvascular proliferation are absent. The occasional or regional occurrence of gemistocytic neoplastic cells is compatible with the diagnosis of fibrillary astrocytoma. (WHO)


pleomorphic xanthoastrocytoma

A WHO grade ll astrocytic tumor with a relatively favorable prognosis. It is characterized by pleomorphic and lipidized cells expressing GFAP often surrounded by a reticulin network and eosinophilic granular bodies. It presents in the superficial cerebral hemispheres and involves the meninges. It typically affects children and young adults.


pilocytic astrocytoma

Pilocytic astrocytoma is a rare subtype of low-grade glioma of the central nervous system characterized by a well circumscribed, often cystic, brain tumor with a discrete mural nodule and long, hair-like projections that extend from the neoplastic astrocytes. Depending on the primary localization and the size of the tumor, patients can present with signs of raised intracranial pressure (headache, vomiting, papilledema), blurred vision, decreased visual acuity, ataxia and/or nystagmus, among others. It is most commonly located in the cerebellum, but occurrence in the hypothalamus, brain stem, optic chiasma, and hemispheres has also been reported.


pilomyxoid astrocytoma

An astrocytic tumor of uncertain relation to pilocytic astrocytoma. It occurs predominantly in infants and young children. It is characterized by a monomorphic architectural pattern, usually associated with the absence of Rosenthal fibers and eosinophilic granular bodies. The clinical course is usually aggressive.


subependymal giant cell astrocytoma

A benign, slowly growing tumor (WHO grade I) typically arising in the wall of the lateral ventricles and composed of large ganglioid astrocytes. It is the most common CNS neoplasm in patients with tuberous sclerosis complex and typically occurs during the first two decades of life. (WHO)


oligodendroglioma

A well-differentiated (WHO grade II), diffusely infiltrating neuroglial tumor, typically located in the cerebral hemispheres. It is composed predominantly of cells which morphologically resemble oligodendroglia. The neoplastic cells have rounded homogeneous nuclei and, on paraffin sections, a swollen, clear cytoplasm ('honeycomb' appearance). (Adapted from WHO)


anaplastic oligodendroglioma

A WHO grade III oligodendroglioma with focal or diffuse malignant morphologic features (prominent nuclear pleomorphism, mitoses, and increased cellularity).


ependymoma

A WHO grade II, slow growing tumor of children and young adults, usually located intraventricularly. It is the most common ependymal neoplasm. It often causes clinical symptoms by blocking cerebrospinal fluid pathways. Key histological features include perivascular pseudorosettes and ependymal rosettes. (WHO)


anaplastic ependymoma

Anaplastic ependymoma is a rare, malignant type of ependymoma that most often arises in the supratentorial region of the brain of children and young adults and that manifests with variable symptoms including headaches, nausea, vision impairment, memory loss and difficulty walking.


oligoastrocytoma

A WHO grade II tumor composed of a conspicuous mixture of two distinct neoplastic cell types morphologically resembling the tumor cells in oligodendroglioma and diffuse astrocytoma. (WHO)


anaplastic oligoastrocytoma

An oligoastrocytoma characterized by the presence of increased cellularity, nuclear atypia, pleomorphism, and high mitotic activity.


angiocentric glioma

Angiocentric glioma (AG) is an extremely rare slow-growing glial neoplasm of the central nervous system, usually arising in a superficial location in the cerebrum, affecting all ages and both sexes, and characterized by intractable seizures and headaches, with most cases being cured by surgical incision alone and therefore having a good prognosis.


chordoid glioma of the third ventricle

A rare, slow-growing neuroepithelial neoplasm of uncertain origin affecting adults. It is located in the third ventricle. It is characterized by the presence of epithelioid cells which express GFAP, and mucinous stroma which contains lymphoplasmacytic infiltrates.


medulloblastoma with extensive nodularity

Medulloblastoma with extensive nodularity (MBEN) is a histological variant of medulloblastoma, an embryonic malignancy, most often located in the inferior medullary velum and then growing into the fourth ventricle, and presenting in infants and young children with symptoms of increased intracranial pressure such as headache, listlessness, vomiting, diplopia and papilledema. It is often associated with Gorlin syndrome and has a relatively good prognosis.


desmoplastic/nodular medulloblastoma

A histological variant of medulloblastoma, an embryonic malignancy, often located in one of the cerebellar hemispheres, occurring most frequently in adults and manifesting with symptoms such as vomiting and headache.


ependymoblastoma

Ependymoblastoma is a rare type of primitive neuroectodermal tumor (PNET) that usually occurs in young children under the age of 2 and is histologically distinguished by the production of ependymoblastic rosettes. It is associated with an aggressive course and a poor prognosis.


choroid plexus neoplasm

An intraventricular papillary neoplasm that originates from the choroid plexus epithelium. It includes the choroid plexus papilloma, atypical choroid plexus papilloma, and choroid plexus carcinoma.


choroid plexus carcinoma

A malignant neoplasm arising from the choroid plexus. It shows anaplastic features and usually invades neighboring brain structures. Cerebrospinal fluid metastases are frequent. (Adapted from WHO)


pineoblastoma

Pineoblastoma is a rare, malignant type of supratentorial primitive neuroectodermal tumor (sPNET), found mainly in children (less than 10% of cases are reported in adults), and located in the pineal region of the brain but that can metastasize along the neuroaxis. As it is the most aggressive of the pineal parenchymal tumors, it is usually associated with a poor prognosis.


extraventricular neurocytoma

Extraventricular neurocytoma (EVN), a variant of central neurocytoma, is a rare neuronal neoplasm, composed of round cells with neuronal differentiation, which is located outside of the ventricular system, usually within the spinal cord or cerebral hemispheres and that manifests with headache, nausea, vomiting, complex partial seizures or focal neurological deficits. In some cases it may exhibit atypical features consistent with aggressive clinical behavior.


gangliocytoma

A well differentiated, slow growing neuroepithelial neoplasm composed of neoplastic, mature ganglion cells.


ganglioglioma

A well differentiated, slow growing neuroepithelial neoplasm composed of neoplastic, mature ganglion cells and neoplastic glial cells. Some gangliogliomas show anaplastic features in their glial component and are considered to be WHO grade III. Rare cases of newly diagnosed gangliogliomas with grade IV (glioblastoma) changes in the glial component have also been reported. (Adapted from WHO)


anaplastic ganglioglioma

A WHO grade III neuroepithelial neoplasm composed of neoplastic, mature ganglion cells and anaplastic glial cells. The anaplastic changes in the glial component and high MIB-1 and TP53 labeling indices may indicate aggressive behavior. However, the correlation of histological anaplasia with clinical outcome is inconsistent. (Adapted from WHO)


papillary glioneuronal tumor

A WHO grade I, indolent and relatively circumscribed brain tumor. Morphologically it is characterized by the presence of astrocytes that line vascular and hyalinized pseudopapillae. In between the pseudopapillae aggregates of neurocytes, large neurons, and ganglioid cells are present.


tumor of meninges

A benign or malignant neoplasm that affects the meninges. The majority of the neoplasms arise from meningothelial cells and are called meningiomas. Non-meningothelial cell neoplasms include mesenchymal, non-meningothelial tumors, hemangiopericytomas, and melanocytic lesions.


meningeal melanocytoma

A usually well differentiated melanocytic neoplasm arising from the meninges. It is characterized by the presence of epithelioid, fusiform, polyhedral, and spindle melanocytes without evidence of hemorrhage, necrosis, or high mitotic activity. Presenting symptoms include headache, vomiting, and neurological manifestations. Complete excision is usually curative.


primary melanoma of the central nervous system

A melanoma that affects the central nervous system. It is characterized by pleomorphism, melanin pigmentation, a high mitotic rate, necrosis, and hemorrhage. It is a highly aggressive and radioresistant tumor. The prognosis is usually poor.


hemangioblastoma

Hemangioblastoma is a rare, benign, highly vascularized tumor of the central nervous system, most often located in the cerebellum or spinal cord, presenting in adulthood and manifesting with dizziness, nausea, malaise, headache, bladder or bowel dysfunction, numbness, weakness and pain in the upper or lower extremities, and often associated with von Hippel-Lindau disease (VHL). Exceptional cases of hemangioblastoma arising outside of the central nervous system have been reported.


neurofibroma

An intraneural or extraneural neoplasm arising from nerve tissues and neural sheaths. It is composed of perineurial-like fibroblasts and Schwann cells. It usually presents as a localized cutaneous lesion and less often as a circumscribed peripheral nerve mass. Patients with neurofibromatosis type 1 present with multiple masses. Neurofibromas which arise from major nerves and plexiform neurofibromas are precursor lesions to malignant peripheral nerve sheath tumors.


malignant triton tumor

Malignant triton tumor (MTT) is a rare aggressive subtype of malignant peripheral nerve sheath tumor (MPNST) characterized histopathologically by focal rhabdomyoblastic differentiation.


lichen planus pigmentosus

Lichen planus (LP) pigmentosus is a rare variant of cutaneous lichen planus characterized by the presence of hyperpigmented lichenoid lesions in sun-exposed or flexural areas of the body.


frontal fibrosing alopecia

Frontal fibrosing alopecia (FFA) is a rare variant of lichen planopilaris characterized by symmetrical, progressive, band-like anterior hair loss of the scalp.


iatrogenic botulism

Iatrogenic botulism is the most recent man-made form of botulism, a rare acquired neuromuscular junction disease with descending flaccid paralysis caused by botulinum neurotoxins (BoNTs), and it may occur as an adverse event after therapeutic or cosmetic use.


epithelioid trophoblastic tumor

An epithelioid trophoblastic tumor is an extremely rare gestational trophoblastic tumor (GTT) which generally occurs several years after pregnancy.


Moyamoya disease

Moyamoya disease (MMD) is a rare intracranial arteriopathy involving progressive stenosis of the cerebral vasculature located at the base of the brain causing transient ischemic attacks or strokes.


mycetoma

Mycetomas are subcutaneous inflammatory pseudotumors containing fungal or actinomycetic (bacteria with branched filaments) granules or grains.


limb-girdle muscular dystrophy

Limb-girdle muscular dystrophy (LGMD) is a heterogeneous group of muscular dystrophies characterized by proximal weakness affecting the pelvic and shoulder girdles. Cardiac and respiratory impairment may be observed in certain forms of LGMD.


angiosarcoma

A malignant tumor arising from the endothelial cells of the blood vessels. Microscopically, it is characterized by frequently open vascular anastomosing and branching channels. The malignant cells that line the vascular channels are spindle or epithelioid and often display hyperchromatic nuclei. Angiosarcomas most frequently occur in the skin and breast. Patients with long-standing lymphedema are at increased risk of developing angiosarcoma.


primary interstitial lung disease specific to childhood


Langerhans cell histiocytosis specific to childhood

Langerhans cell histiocytosis that occurs during childhood.


Langerhans cell histiocytosis specific to adulthood

Langerhans cell histiocytosis that occurs during adulthood.


neuroepithelioma

Peripheral neuroepithelioma is a rare noncentral nervous system tumor with evidence of primitive neuroectodermal differentiation.


pseudomyxoma peritonei

Pseudomyxoma peritonei is characterized by disseminated intra-peritoneal mucinous tumors and mucinous ascites in the abdomen and pelvis.


cephalocele

A congenital neural tube closure defect resulting in the protrusion of the brain through a skull opening. When the protrusion includes the meninges, the term encephalomeningocele is used.


primary tethered cord syndrome

Primary tethered cord syndrome is a genetic, non-syndromic congenital malformation of the neurenteric canal, spinal cord and column characterized by progressive neurologic deterioration (pain, sensorimotor deficits, abnormal gait, decreased tone or abnormal reflexes), musculoskeletal changes (foot deformities and asymmetry, muscle atrophy, limb weakness and numbness, gait disturbances, scoliosis) and/or genitourinary manifestations (bladder and bowel dysfunction). Midline cutaneous stigmata in the lumbosacral region, such as turfs of hair, skin appendages, dimples, subcutaneous lipomas, skin discoloration or hemangiomas, are frequently associated.


onchocerciasis

Onchocerciasis is a form of filariasis, caused by the parasitic worm Onchocerca volvulus, transmitted by the black fly. The infection can either be asymptomatic or manifest as an ocular disease (river blindness) with itchy eyes, erythema, photophobia, onchodermatitis or onchocercal skin disease (classified into acute papular, chronic papular, lichenified, atrophic, and depigmentated) and onchocercomas (over bony prominences). Other classic clinical manifestations are ichthyosis-like lesions (''lizard skin'') and ''hanging groin'', which may be associated with lymphadenopathy.


idiopathic pulmonary arterial hypertension

Idiopathic pulmonary arterial hypertension (IPAH) is a sporadic form of pulmonary arterial hypertension (PAH) characterized by elevated pulmonary arterial resistance leading to right heart failure. IPAH is progressive and potentially fatal and not associated with an underlying condition or family history of PAH.


multiple endocrine neoplasia

Multiple endocrine neoplasia (MEN) is a group of rare inherited cancer syndromes characterized by the development of two or more endocrine gland tumors, sometimes with tumor development in other tissues or organs.


familial hyperinsulinism

An instance of hyperinsulinism (disease) that is caused by an inherited modification of the individual's genome.


osteopetrosis

Osteopetrosis, also known as marble bone disease, is a descriptive term that refers to a group of rare, heritable disorders of the skeleton characterized by increased bone density on radiographs.


calciphylaxis

Calciphylaxis is a disease in which blood vessels (veins and arteries) become blocked by a build-up of calcium in the walls of the vessels, preventing blood from flowing to the skin or internal organs. The lack of blood flow (ischemia) damages healthy tissue and causes itto die (necrosis). The most obvious and frequent symptom of calciphylaxis is damage to the skin, as ulcers can developand become infected easily. Calciphylaxis can also affect fat tissue, internal organs, and skeletal muscle, causing infections, pain, and organ failure.These symptoms are often irreversible, and many individuals with calciphylaxis may not survive more thana few months after they are diagnosed due to infection that spreads throughout the body (sepsis), or organ failure. The exact cause of calciphylaxis is unknown. Treatments may include medications to reduce pain, antibiotics to treat infections, and various approaches to preventing the development or worsening of this condition.


rapidly progressive glomerulonephritis

Inflammation of the glomeruli that is characterized by a rapid loss in renal function with glomerular crescent formation observed on biopsy; it is often seen in patients with concomitant autoimmune disease, like Goodpasture's syndrome or systemic lupus erythematosus.


panuveitis

A disorder characterized by inflammation of the entire uvea which includes the iris, ciliary body, and choroid. Causes include systemic infections, sarcoidosis, and cancers.


autosomal recessive congenital ichthyosis

Autosomal recessive form of inherited ichthyosis.


frontotemporal dementia

Frontotemporal dementia (FTD) comprises a group of neurodegenerative disorders, characterized by progressive changes in behavior, executive dysfunction and language impairment, as a result of degeneration of the medial prefrontal and frontoinsular cortices. Four clinical subtypes have been identified: semantic dementia, progressive non-fluent aphasia, behavioral variant FTD and right temporal lobar atrophy.


alveolar echinococcosis

Alveolar echinococcosis (AE) is a rare parasitic disorder that occurs after ingestion of eggs of Echinococcus multilocularis. AE is characterized by an initial asymptomatic incubation period of many years followed by a chronic course where the clinical manifestations include epigastric pain and jaundice.


IgG4-related disease

A recently described mass-forming lesion that occurs in the pancreas, submandibular glands, lacrimal glands, lymph nodes, and hepatobiliary tract. It is characterized by the presence of marked tissue sclerosis and infiltration by numerous plasma cells. The plasma cells show immunohistochemical staining for IgG4 and the serum IgG4 levels are often increased.


reversible cerebral vasoconstriction syndrome

Reversible cerebral vasoconstriction syndrome (RCVS) is an infrequent cerebrovascular disorder characterized by severe headaches with or without focal neurological deficits or seizures, and a reversible segmental and multifocal vasoconstriction of cerebral arteries.


Ehlers-Danlos syndrome, vascular type

Ehlers-Danlos syndrome type IV, also known as the vascular type of Ehlers-Danlos syndrome (EDS), is an inherited connective tissue disorder defined by characteristic facial features (acrogeria) in most patients, translucent skin with highly visible subcutaneous vessels on the trunk and lower back, easy bruising, and severe arterial, digestive and uterine complications, which are rarely, if at all, observed in the other forms of EDS.


autosomal recessive hypophosphatemic rickets

Autosomal recessive hypophosphatemic rickets (ARHR) is a hereditary renal phosphate-wasting disorder characterized by hypophosphatemia, rickets and/or osteomalacia and slow growth.


fatal multiple mitochondrial dysfunctions syndrome

Multiple mitochondrial dysfunctions syndrome describes a group of rare inborn errors of energy metabolism due to defects in mitochondrial [4Fe-4S] protein assembly. Patients present with a neonatal/infancy onset of metabolic lactic acidosis (that may be associated with hyperglycinemia and other abnormal metabolic testing results), muscular hypotonia, absence of psychomotor development or developmental regression, as well as abnormal neuroimaging findings (including leukodystrophy, brain developmental defects, white matter abnormalities, cerebral atrophy), and other variable clinical features (e.g., optic atrophy, cardiomyopathy, pulmonary hypertension, seizures, and dysmorphic features). Early fatal outcome is usual.


juvenile nasopharyngeal angiofibroma

Juvenile nasopharyngeal angiofibroma (JNA) is a rare and benign but locally aggressive fibrovascular tumor arising from the posterolateral wall of the nasopharynx, which affects mainly young and adolescent males (onset usually occurring between 7-19 years of age) and that presents as a mass in the nasopharynx and nasal cavity, leading to manifestations such as nasal obstruction, epistaxis, profound facial swelling, proptosis or diplopia. Although slowly progressive, it has a high rate of recurrence and sometimes invades adjacent structures.


Epstein-Barr virus-positive diffuse large B-cell lymphoma of the elderly is a rare form of diffuse large B-cell lymphoma occurring most commonly in patients over the age of 50 (usually between 70-75 years of age), without overt immunodeficiency, and presenting with nodal and extranodal involvement (in sites such as the stomach, lung, skin and pancreas) and B symptoms (fever, night sweats, weight loss). The tumor is characterized by an aggressive course and a short survival rate.


plasmablastic lymphoma

An aggressive diffuse large B-cell lymphoma frequently arising in the setting of HIV infection and characterized by the presence of large neoplastic cells resembling B-immunoblasts which have the immunophenotypic profile of plasma cells. Sites of involvement include the oral cavity, sinonasal cavity, skin, soft tissues, gastrointestinal tract, and bone.


POEMS syndrome

POEMS syndrome is a paraneoplastic syndrome characterized by polyradiculoneuropathy (P), organomegaly (O), endocrinopathy (E), clonal plasma cell disorder (M), and skin changes (S). Other features include papilledema, extravascular volume overload, sclerotic bone lesions, thrombocytosis/erythrocytosis, and elevated VEGF levels.


poliomyelitis

An acute infectious disorder that affects the nervous system. It is caused by the poliovirus. The virus spreads by direct contact, and can be prevented by prophylaxis with the polio vaccine.


reactive arthritis

Reactive arthritis (ReA) is an autoimmune disorder belonging to the group of seronegative spondyloarthropathies and is characterized by the classic triad of arthritis, urethritis and conjunctivitis.


epithelioid sarcoma

An aggressive malignant neoplasm of uncertain differentiation, characterized by the presence of epithelioid cells forming nodular patterns. The nodules often undergo central necrosis, resulting in a pseudogranulomatous growth pattern. It usually occurs in young adults. The most common sites of involvement are the extremities (distal-type epithelioid sarcoma), and less frequently the pelvis, perineum, and genital organs (proximal-type epithelioid sarcoma).


rapid-onset childhood obesity-hypothalamic dysfunction-hypoventilation-autonomic dysregulation syndrome

A very rare disorder that appears after the first year and a half of life in previously healthy children. It is characterized by rapid-onset weight gain, hypothalamic dysfunction, breathing abnormalities, and autonomic system dysregulation. The hypothalamic dysfunction manifestations include inability to maintain normal water balance, high prolactin levels, low thyroid, low cortisol, and early or late puberty. The breathing abnormalities include sleep apnea and alveolar hypoventilation, requiring ventilation support. The autonomic system dysregulation includes eye abnormalities, intestinal abnormalities, temperature dysregulation, and low heart rhythm. This disorder requires early recognition because it may lead to cardiorespiratory arrest. Up to 40% of the patients develop tumors of neural crest origin.


postpoliomyelitis syndrome

Postpoliomyelitis syndrome (PPS) is a neurologic disorder characterized by the development of new neuromuscular symptoms such as progressive muscular weakness or abnormal muscle fatigability occurring in survivors of the acute paralytic form of poliomyelitis, 15-40 years after recovery from the disease, and that is unexplained by other medical causes. Other manifestations that can occur gradually include generalized fatigue, muscle atrophy, muscle and joint pain, intolerance to cold, and difficulties sleeping, swallowing or breathing.


congenital pseudoarthrosis of the tibia

A condition characterized by non-union of the tibia, which is present at birth. It is usually associated with neurofibromatosis type 1.


leukocyte adhesion deficiency

Leukocyte adhesion deficiency (LAD) is a primary immunodeficiency characterized by defects in the leukocyte adhesion process, marked leukocytosis and recurrent infections.


tick-borne encephalitis

Tick-borne encephalitis is caused by an arbovirus of the Flaviviridae family (tick-borne encephalitis virus, TBEV), transmitted principally by the bite of the Ixodes ricinus tick. The symptomology is biphasic, with the initial phase being associated with a flu-like illness and the second phase (occurring in less than 10% of patients) with symptoms of meningitis or, more rarely, meningoencephalitis.


chronic intestinal pseudoobstruction

Chronic intestinal pseudo-obstruction (CIPO) is a rare gastrointestinal motility disorder characterized by recurring episodes resembling mechanical obstruction in the absence of organic, systemic, or metabolic disorders, and without any physical obstruction being detected by X-ray or during surgery. CIPO develops predominantly in children and may be present at birth.


A syndrome characterized by the association of gastrointestinal dysmotility, peripheral neuropathy, chronic progressive external ophthalmoplegia and leukoencephalopathy.


pituitary adenocarcinoma

A rare adenocarcinoma with poor prognosis, arising from the adenohypophysial cells of the anterior lobe of the pituitary gland or pre-existing adenomas. The majority are hormonally functioning neoplasms, usually producing prolactin or ACTH. The diagnosis is based on the presence of metastases. Syndromes associated with pituitary gland carcinomas include hyperprolactinemia, Cushing disease, and acromegaly.


carcinoma of the ampulla of vater

A carcinoma arising from the ampulla of Vater. The vast majority of cases are adenocarcinomas. Signs and symptoms include jaundice, abdominal pain, anorexia, nausea, vomiting, and weight loss.


indolent B-cell non-Hodgkin lymphoma

A B-cell non-Hodgkin lymphoma with an indolent clinical course. Representative examples include grade 1 and grade 2 follicular lymphoma, marginal zone lymphoma, and lymphoplasmacytic lymphoma.


aggressive B-cell non-Hodgkin lymphoma

A B-cell non-Hodgkin lymphoma with an aggressive clinical course. This category includes B lymphoblastic lymphoma, subtypes of diffuse large B-cell lymphoma, Burkitt lymphoma, grade 3 follicular lymphoma, and mantle cell lymphoma.


diffuse large B-cell lymphoma of the central nervous system

A diffuse large B-cell lymphoma arising from the central nervous system.


T-cell/histiocyte rich large B cell lymphoma (THRLBCL) is a rare variant of diffuse large B-cell lymphoma (DLBCL), mainly affecting middle-aged men and often not being discovered until an advanced disease stage, with involvement of the spleen, liver and bone marrow occurring at a greater frequency than in DLBCL. It is often difficult to diagnose due to its similarity with other lymphoid diseases such as classic Hodgkin lymphoma and nodular lymphocyte-predominant Hodgkin lymphoma and has an aggressive clinical course.


primary cutaneous anaplastic large cell lymphoma

Primary cutaneous anaplastic large cell lymphoma (C-ALCL) is a rare T-cell non-Hodgkin lymphoma that affects the skin and generally shows no extracutaneous involvement at presentation. It belongs to the spectrum of primary cutaneous CD30+ lymphoproliferative disorders along with lymphomatoid papulosis with which it shares overlapping clinical and histopathologic features.


hairy cell leukemia variant

Hairy Cell Leukemia variant (HCL-V) is defined as a rare and indolent form of small, mature, B-cell leukemia characterized by splenomegaly, an elevated white blood cell (WBC) count and hyper-cellular bone marrow. HCL-V is more aggressive and resistant to therapy than classical HCL (HCL-C).


ALK-positive anaplastic large cell lymphoma (ALK+ ALCL) is a type of ALCL, a rare and aggressive peripheral T-cell non-Hodgkin lymphoma affecting lymph nodes and extranodal sites, which is characterized by the expression of a protein called anaplastic lymphoma kinase (ALK).


ALK-negative anaplastic large cell lymphoma (ALK- ALCL) is a type of ALCL, a rare and aggressive peripheral T-cell non-Hodgkin lymphoma affecting lymph nodes and extranodal sites, which is characterized by the lack of expression of a protein called anaplastic lymphoma kinase (ALK).


marginal zone lymphoma

A usually indolent mature B-cell lymphoma, arising from the marginal zone of lymphoid tissues. It is characterized by the presence of small to medium sized atypical lymphocytes. It comprises three entities, according to the anatomic sites involved: extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue, which affects extranodal sites (most often stomach, lung, skin, and ocular adnexa); nodal marginal zone B-cell lymphoma, which affects lymph nodes without evidence of extranodal disease; and splenic marginal zone B-cell lymphoma, which affects the spleen and splenic hilar lymph nodes, bone marrow, and often the peripheral blood.


epidermolysis bullosa simplex

Epidermolysis bullosa simplex (EBS) is a group of hereditary epidermolysis bullosa (HEB) disorders characterized by skin fragility resulting in intraepidermal blisters and erosions that occur either spontaneously or after physical trauma.


pituitary tumor

A benign or malignant neoplasm affecting the pituitary gland. The vast majority are adenomas arising from the anterior lobe of the pituitary gland.


junctional epidermolysis bullosa

Junctional epidermolysis bullosa (JEB) is a form of inherited epidermolysis bullosa characterized by involvement of the skin and mucous membranes, and is defined by the formation of blistering lesions between the epidermis and the dermis at the lamina lucida level of the cutaneous basement membrane zone and by healing of lesions with atrophy and/or exuberant granulation tissue formation.


PTEN hamartoma tumor syndrome

A group of clinically heterogeneous disorders united by a germline PTEN mutation and the involvement of derivatives of all 3 germ cell layers, manifesting with hamartomas, overgrowth and neoplasia. Currently, subsets carrying clinical diagnoses of Cowden syndrome, Bannayan-Riley-Ruvalcaba syndrome, Proteus and Proteus-like syndromes and SOLAMEN syndrome belong to PHTS.


Sydenham chorea

A neurological disorder characterized by rapid, jerky, irregular, and involuntary movements (chorea), especially of the face and limbs. Additional symptoms may include muscle weakness, slurred speech, headaches, and seizures.


glycogen storage disease due to acid maltase deficiency, infantile onset

Glycogen storage disease due to acid maltase deficiency, infantile onset is the most severe form of glycogen storage disease due to acid maltase deficiency, characterized by cardiomegaly with respiratory distress, muscle weakness and feeding difficulties. It is often fatal.


gangliosidosis

A group of autosomal recessive lysosomal storage disorders marked by the accumulation of gangliosides. They are caused by impaired enzymes or defective cofactors required for normal ganglioside degradation in the lysosomes. Gangliosidoses are classified by the specific ganglioside accumulated in the defective degradation pathway.


GM2 gangliosidosis

A group of recessively inherited diseases characterized by the intralysosomal accumulation of G(M2) GANGLIOSIDE in the neuronal cells. Subtypes include mutations of enzymes in the BETA-N-ACETYLHEXOSAMINIDASES system or G(M2) ACTIVATOR PROTEIN leading to disruption of normal degradation of GANGLIOSIDES, a subclass of ACIDIC GLYCOSPHINGOLIPIDS.


rheumatic fever

A post-bacterial multisystem inflammatory disease occurring as a post-infectious, nonsuppurative sequela of untreated streptococcus pyogenes (Group A streptococcus [GAS]) pharyngitis, and mainly occurs in individuals aged 5 to 15 years. The most common presenting signs are fever, migratory polyarthritis and carditis.


hypoalphalipoproteinemia

A metabolic disorder characterized by deficiency of high density (alpha) lipoprotein in the blood.


hypobetalipoproteinemia

A group of lipoprotein metabolism disorders that are characterized by permanently low levels (below the 5th percentile) of apolipoprotein B and LDL cholesterol.


melioidosis

An infection that is caused by Burkholderia pseudomallei, which is found in soil and water; symptoms vary widely, but most commonly include fever, cough, pneumonia, arthralgia, myalgia, and skin ulceration.


lamellar ichthyosis

A keratinization disorder characterized by the presence of large scales all over the body without significant erythroderma.


Epstein-Barr virus-associated gastric carcinoma

Epstein-Barr virus (EBV)-associated gastric carcinoma (EBVaGC) is a rare form of gastric carcinoma (seen in approximately 10% of cases) with a male predominance, characterized by a latent EBV infection in gastric carcinoma cells, diffuse-type histology, a proximal location (in the body and cardia of the stomach) and a relatively favorable prognosis.


ameloblastoma

The most common odontogenic tumor, arising from the epithelial component of the embryonic tooth and usually affecting the molar-ramus region of the mandible or maxilla. Although most ameloblastomas are morphologically and clinically benign, they may cause extensive local destruction, recur, or metastasize.


primary systemic amyloidosis

Primary systemic amyloidosis (PSA) is a form of AL amyloidosis caused by the aggregation and deposition of insoluble amyloid fibrils derived from misfolded monoclonal immunoglobulin light chains usually produced by a plasma cell tumor and characterized by multiple organ involvement.


malignant peripheral nerve sheath tumor

Malignant peripheral nerve sheath tumor (MPNST) is a rare and often aggressive soft tissue sarcoma occurring in a wide range of anatomical sites.


congenital pulmonary sequestration

A rare congenital abnormality of the lungs. It consists of a mass of lung parenchyma that does not communicate with the bronchial tree and receives its blood supply from the systemic circulation instead of the pulmonary circulation.


Sezary syndrome

Sezary syndrome (SS) is an aggressive form of cutaneous T-cell lymphoma characterized by a triad of erythroderma, lymphadenopathy and circulating atypical lymphocytes (Sezary cells).


hypersensitivity pneumonitis

Hypersensitivity pneumonitis (HP) is a pulmonary disease with symptoms of dyspnea and cough resulting from the inhalation of an antigen to which the subject has been previously sensitized.


acute erythroid leukemia

An acute myeloid leukemia characterized by a predominant immature erythroid population. There are two subtypes recognized: erythroleukemia and pure erythroid leukemia. (WHO, 2001)


paraquat poisoning

Paraquat poisoning is a rare intoxication with paraquat (a non-selective bipyridilium herbicide that has been banned in Europe), usually occurring through ingestion of the poison, and that presents with caustic injury of the oral cavity and pharynx, as well as nausea, vomiting, epigastric pain, lethargy, loss of consciousness and fever. Patients may develop potentially life-threatening complications such as hepatic dysfunction, acute tubular necrosis and renal insufficiency, and respiratory failure (due to pulmonary fibrosis) due to its inherent toxicity and lack of effective treatment. Intoxication via inhalation, injection and dermal or mucus contact have also been reported.


congenital pulmonary veins atresia or stenosis

Congenital pulmonary vein (PV) stenosis or atresia is a rare progressive life-threatening great vessels anomaly characterized by narrowing and obstruction of one or more normally positioned PV at their junction with the left atrium, that usually presents during early infancy with dyspnea, tachypnea, and repeated pulmonary infections, and eventually, when all PV of one lung are affected, results in pulmonary hypertension (PH) and consecutive pulmonary arterial hypertension (PAH). It may manifest as an isolated lesion or associated with other cardiac defects such as congenital pulmonary venous return anomaly and septal defects.


hantavirus pulmonary syndrome

An infection caused by Hantaviruses. It manifests with flu-like symptoms but it rapidly progresses to life-threatening respiratory problems.


papillary renal cell carcinoma

A rare subtype of renal cell carcinoma, arising from the renal tubular epithelium and showing a papillary growth pattern, which typically manifests with hematuria, flank pain, palpable abdominal mass or nonspecific symptoms, such as fatigue, weight loss or fever. Symptoms related to metastatic spread, such as bone pain or persistent cough, are frequently associated since early diagnosis is not common. It is typically multifocal, bilateral, and in most cases sporadic, although different hereditary syndromes, such as Hereditary leiomyoma renal cell carcinoma, Birt-Hogg-DubC) syndrome and Tuberous sclerosis, may predispose to the development of papillary renal cell carcinoma.


chromophobe renal cell carcinoma

Chromophobe renal cell carcinoma is a rare subtype of renal cell carcinoma, originating from the intercalating cells of the collecting ducts and macroscopically manifesting as a well-circumscribed, highly lobulated, solid tumor that is usually diagnosed at an early stage. It is frequently asymptomatic, or may present with nonspecific symptoms, such as weight loss, fever or fatigue. The classic presentation observed in renal tumors (hematuria, flank pain and palpable mass) is occasionally observed and usually indicates an advanced stage of the disease. It is most frequently sporadic however, several familial cases, associated with Birt-Hogg DubC) syndrome, have been described.


MIT family translocation renal cell carcinoma

MiT family translocation renal cell carcinoma (t-RCC) is a rare subtype of renal cell carcinoma with recurrent genetic abnormalities, harboring rearrangements of the TFE3 (Xp11 t-RCC) or TFEB [t(6;11) t-RCC] genes. The t(6;11) t-RCC has distinctive histologic features of biphasic appearance with larger epitheloid and smaller eosinophilic cells. The symptoms are usually non-specific and include hematuria, flank pain, palpable abdominal mass and/or systemic symptoms of anemia, fatigue and fever.


tubulocystic renal cell carcinoma

Tubulocystic renal cell carcinoma is an extremely rare subtype of renal cell carcinoma most frequently characterized by a small, solitary, well-circumscribed, unencapsulated renal tumor composed of multiple small to medium-sized cysts with a white or gray, spongy ("bubble wrap-like") cut surface. Patients are usually asymptomatic or could manifest with abdominal pain, abdominal distension and/or hematuria. Progression, recurrence and metastasis rarely occur although lymph node, bone, pleura and liver mestatsis have been reported.


dehydrated hereditary stomatocytosis

Dehydrated hereditary stomatocytosis (DHS) is a rare hemolytic anemia characterized by a decreased red cell osmotic fragility due to a defect in cation permeability, resulting in red cell dehydration and mild to moderate compensated hemolysis. Pseudohyperkalemia (loss of potassium ions from red cells on storage at room temperature) is sometimes observed.


autoimmune lymphoproliferative syndrome

Autoimmune lymphoproliferative syndrome (ALPS) is a rare, inherited disorder characterized by non-malignant lymphoproliferation, multilineage cytopenias, and a lifelong increased risk of Hodgkin's and non-Hodgkin's lymphoma.


syringomyelia

Syringomyelia is characterized by cerebrospinal fluid (CSF)-filled cavities (syrinx) inside the spinal cord, either as a result of a known cause (secondary syringomyelia, SS) or, more rarely, due to an unknown cause (primary syringomyelia, PS).


catecholaminergic polymorphic ventricular tachycardia

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a severe genetic arrhythmogenic disorder characterized by adrenergically induced ventricular tachycardia (VT) manifesting as syncope and sudden death.


Takayasu arteritis

A rare inflammatory large-vessel vasculitis primarily affecting the aorta and its major branches, but also other large vessels, causing stenosis, occlusion, or aneurysm.


lead poisoning

5 ug/dL) is reported to lead to irreversible effects such as loss of cognition, shortening of attention span, alteration of behavior, dyslexia, attention deficit disorder, hypertension, renal impairment, immunotoxicity and toxicity to the reproductive organs.


mercury poisoning

Mercury poisoning is caused mainly through ingestion or inhalation of any of the 3 forms of mercury, elemental, organic, and inorganic. Exposure to elemental mercury affects the pulmonary (inhalation of mercury vapors causes coughing, chills, fever, shortness of breath), dermatological (mild swelling, vesiculation, scaling, irritation, urticaria, erythema and allergic contact dermatitis accompanied by pain), and peripheral and central nervous (CNS) systems (depression, paranoia, extreme irritability, hallucinations, inability to concentrate, memory loss, hands, head, lips, tongue, jaw and eyelids tremors, weight loss, perpetually low body temperature, drowsiness, headaches, insomnia, fatigue). Exposure to inorganic mercury generally causes development of a metallic taste, local oropharyngeal pain, nausea, vomiting, bloody diarrhea, colic abdominal pain, renal dysfunction and, neurologic abnormalities; while that to organic mercury can lead to delayed neurotoxicity.


hydroa vacciniforme

A rare skin disorder of unknown etiology affecting children. It is a photodermatitis, characterized by the formation of vesicles and scarring on sun exposed areas.


hyper-IgE syndrome

A condition that is characterized by elevated serum IgE, dermatitis, and respiratory infections.


idiopathic hypersomnia

Idiopathic hypersomnia is a sleep disorder classified in two forms: idiopathic hypersomnia with long sleep time and idiopathic hypersomnia without long sleep time.


heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is a drug-induced, immune-mediated prothrombotic disorder associated with thrombocytopenia and venous and/or arterial thrombosis.


pediatric hepatocellular carcinoma

Pediatric hepatocellular carcinoma (pediatric HCC) is a rare, aggressive, malignant hepatic tumor that develops mainly in children over 10 years of age.


meningococcal meningitis

An acute bacterial disease caused by Neisseria meningitides that presents usually, but not always, with a rash (non blanching petechial or purpuric rash), progressively developing signs of meningitis (fever, vomiting, headache, photophobia, and neck stiffness) and later leading to confusion, delirium and drowsiness. Neck stiffness and photophobia are often absent in infants and young children who may manifest nonspecific signs such as irritability, inconsolable crying, poor feeding, and a bulging fontanel. Meningococcal meningitis may also present as part of early or late onset sepsis in neonates. The disease is potentially fatal. Surviving patients may develop neurological sequelae that include sensorineural hearing loss, seizures, spasticity, attention deficits and intellectual disability.


tuberculosis

A chronic, recurrent infection caused by the bacterium Mycobacterium tuberculosis. Tuberculosis (TB) may affect almost any tissue or organ of the body with the lungs being the most common site of infection. The clinical stages of TB are primary or initial infection, latent or dormant infection, and recrudescent or adult-type TB. Ninety to 95% of primary TB infections may go unrecognized. Histopathologically, tissue lesions consist of granulomas which usually undergo central caseation necrosis. Local symptoms of TB vary according to the part affected; acute symptoms include hectic fever, sweats, and emaciation; serious complications include granulomatous erosion of pulmonary bronchi associated with hemoptysis. If untreated, progressive TB may be associated with a high degree of mortality. This infection is frequently observed in immunocompromised individuals with AIDS or a history of illicit IV drug use.


soft tissue sarcoma

A malignant neoplasm arising from muscle tissue, adipose tissue, blood vessels, fibrous tissue, or other supportive tissues excluding the bones.


thymic epithelial neoplasm

An epithelial neoplasm that affects the thymus gland. This category includes thymomas and carcinomas.


viral hemorrhagic fever

A viral infectious disease caused by RNA viruses in the Arenaviridae, Bunyaviridae, Filoviridae, or Flaviviridae family, and characterized by a severe multisystem syndrome, with damage to the vascular system and hemorrhaging.


familial Mediterranean fever

Familial Mediterranean fever (FMF) is an autoinflammatory disorder characterized by recurrent short episodes of fever and serositis resulting in pain in the abdomen, chest, joints and muscles.


Vogt-Koyanagi-Harada disease

A bilateral, chronic, diffuse granulomatous panuveitis typically characterized by serous retinal detachment and frequently associated with neurological (meningitis), auditory, and dermatological alterations.


West syndrome

West syndrome (or infantile spasms) is characterized by the association of clusters of axial spasms, psychomotor retardation and an hypsarrhythmic interictal EEG pattern. It is the most frequent type of epileptic encephalopathy. It may occur in otherwise healthy infants and in those with abnormal cognitive development.


Wolfram syndrome

Wolfram syndrome (WS) also known as DIDMOAD, is a neurodegenerative disorder characterized by type I diabetes mellitus (DM), diabetes insipidus (DI), sensorineural deafness (D), bilateral optical atrophy (OA) and neurological signs. Other related problems are urinary tract atony, ataxia, peripheral neuropathy, psychiatric disorders and/or seizures. 2 types of WS may be distinguished: type 1 and type 2 (WS1 and WS2).


epidermal nevus syndrome

A syndrome characterized by lesions occurring on the face, scalp, or neck which consist of congenital hypoplastic malformations of cutaneous structures and which over time undergo verrucous hyperplasia. Additionally it is associated with neurological symptoms and skeletal, ophthalmological, urogenital, and cardiovascular abnormalities.


galactosemia

Galactosemia is a group of rare genetic metabolic disorders characterized by impaired galactose metabolism resulting in a range of variable manifestations encompassing a severe, life-threatening disease (classic galactosemia), a rare mild form (galactokinase deficiency) causing cataract, and a very rare form with variable severity (galactose epimerase deficiency) resembling classic galactosemia in the severe form.