Malignant fibrous histiocytoma (malignant fibrous xanthoma: xanthosarcoma) of bone.

Seven cases of malignant fibrous histiocytoma of bone are documented. In addition to typical histologic features such as the presence of a storiform pattern, histiocytic and fibrocytic cell types and severe cellular atypism, in five cases there were areas in which osteoclast-type giant cells were prominent and the lesion resembled a giant cell tumor. Three of the seven patients developed pulmonary metastases within two years of amputation, one developed extensive local recurrence including soft tissue and vascular invasion, and the other three are without evidence of disease but have been followed for only short periods.