Undifferentiated high-grade pleomorphic sarcoma (UHPS): Diagnostic criteria, differential diagnosis, and treatment. An attempt to erasure the misnomer MFH

BACKGROUND: For many years malignant fibrous histiocytoma (MFH) was accepted to be the most common soft tissue sarcoma in adults, its histiogenesis, however, remained controversial. METHODS: Review of the current status of MFH. RESULTS: Within the last two decades several studies demonstrated that MFH has been used as a waste paper basket for several better classifiable, poorly differentiated soft tissue sarcomas. Therefore, reclassification of these tumors could led to better prognostification. CONCLUSIONS: In the 21st century with the insight of immunohistochemistry as well as improved cytogenetic and molecular diagnostic the term high-grade undifferentiated pleomorphic sarcoma (so-called MFH) should be restricted to a group of soft tissue malignancies without a specific line of differentiation. Better classification of various high-grade sarcomas may contribute to more specific treatment options and hence lead to improved survival for patients.