Malignant fibrous histiocytoma of the maxillary sinus

Malignant fibrous histiocytoma (MFH) is one of the most common soft-tissue sarcomas in adults (1, 2). The extremities and retroperitoneum are the usual locations. These tumors have also been reported to arise in bone; however, the maxillary sinus is an unusual site (3). Nineteen previous cases of MFH of the maxillary sinus are described in the literature. In all these cases, a portion of the tumor displayed the diagnostic microscopic features. Although it is infrequent in this locale, MFH should be included in the differential diagnosis when the pathologist is confronted with a spindle-cell tumor. We recently studied such a case in a man with nasal obstruction. The lesion exhibited the characteristic fibroblastic cells arranged in a cart-wheel pattern, abundant histiocytes, and atypical multinucleated giant cells. Immunohistochemistry was positive for alpha₁-antitrypsin and S-100 protein. Ultrastructural studies were nonspecific but consistent with a mesenchymal neoplasm.