Malignant fibrous histiocytoma of the mandible - A case report and review of published case reports.

The natural history of malignant fibrous histiocytoma (MFH) is still heavily debated. It's anonymous natural history is precisely denoted by its new adapted terminology 'undifferentiated pleomorphic sarcoma (UPS)'. Thus to diagnose a lesion as UPS, it is vital to correlate its histopathological features along with its immunohistochemical (IHC) expressions to confirm the tumor cell lineage. MFH is extremely rare in mandible with the literature search in PubMed database revealing only 13 case reports of MFH involving the mandible. Among these, only 7 case reports provide IHC details of the case. Without IHC data it is not possible to determine the accuracy of the diagnosis in the remaining 6 cases. Here we report an additional 8th case of MFH involving the ramus and angle of the mandible. Histopathology revealed proliferating malignant spindle cells interspersed with histiocyte-like cells. The tumor cells were strongly positive for vimentin and CD68 and were negative for S-100, epithelial membrane antigen (EMA) and cytokeratin (CK). The diagnosis was made by correlating the histopathological findings with the IHC profile. The report also provides the data (clinical, radiographic, histopathological, immunohistochemical features and treatment details) extracted from the 7 confirmed MFH case reports involving the mandible.