Malignant fibrous histiocytoma of soft tissue: an abandoned diagnosis.

Malignant fibrous histiocytoma (MFH) has been regarded as the most common soft-tissue sarcoma of adult life. Since it was first recognized in the early 1960s, however, MFH has been plagued by controversy in terms of both its histogenesis and its validity as a clinicopathologic entity. The latest World Health Organization classification no longer includes MFH as a distinct diagnostic category but rather as subtypes of an undifferentiated pleomorphic sarcoma. In this article, we review the current understanding of the histologic subtype classification of tumors previously diagnosed as MFH and its relation to clinical outcomes.