The existence of "malignant fibrous histiocytoma" ("MFH") as a distinct entity is controversial. Previously accepted as the most common sarcoma affecting adults, it is now known to comprise a heterogeneous group of tumors without a specific known line of differentiation. Reclassification of many tumors in this group afforded better prognostication, but traditional treatments still apply. Pleomorphic soft tissue tumors for which a line of differentiation is debatable are presently categorized as undifferentiated pleomorphic sarcoma.
(c) 2008 Wiley-Liss, Inc.