Fibroxanthosarcoma of the soft tissues.A type of malignant fibrous histiocytoma

Abstract

The clinical and pathologic features of 30 soft tissue tumors which have a storiform fibrous stroma and bizarre histiocytes and giant cells are reviewed. Because of the resemblance of these lesions to the fibrous histiocytomas and because three of the tumors metastasized, they have been designated as fibroxanthosarcomas. Local recurrence was also common. Fibroxanthosarcoma occurs in many areas of the soft tissues but most commonly in the extremities. Histologically, it resembles storiform fibrous xanthoma (dermatofibrosarcoma protuberans) but can be separated from this entity by the presence of anaplastic bizarre giant cells and numerous mitoses. A proposed nomenclature for the fibrous histiocytomas is also presented. It is concluded that fibroxanthosarcoma is a distinctive malignant fibrous histiocytoma with a bizarre histologic pattern which can be distinguished from other soft tissue sarcomas and from the other fibrous histiocytomas.