label: Usual Interstitial Pneumonia
label_lc: usual interstitial pneumonia
description: Interstitial pneumonia characterized by the presence of fibrosis in the interstitial lung tissue.  The pathologic diagnosis is based on the identification of fibrotic lesions at different stages of development within a lung biopsy specimen.  Typically there are foci of normal lung parenchyma alternating with interstitial inflammation and honeycombing. The term usual interstitial pneumonia sometimes is used interchangeably with idiopathic interstitial fibrosis.  The two terms are not entirely synonymous.  Usual interstitial pneumonia may be associated with other conditions such as connective tissue disorders and asbestosis.  The diagnosis of idiopathic interstitial fibrosis requires the exclusion of such conditions.  Patients with usual interstitial pneumonia present with progressive dyspnea, cough, and restrictive pulmonary function abnormalities.  The prognosis is usually poor.