label: Undifferentiated Soft Tissue Sarcoma
label_lc: undifferentiated soft tissue sarcoma
description: "A term that refers to a heterogeneous group of uncommon soft tissue sarcomas that do not show an identifiable line of differentiation using currently available technologies.  This is a diagnosis of exclusion and includes undifferentiated pleomorphic sarcoma (also known as malignant fibrous histiocytoma), undifferentiated spindle cell sarcoma, undifferentiated round cell sarcoma, and undifferentiated epithelioid sarcoma."