Primary Malignant Fibrous Histiocytoma of Bone

A review of over 400 primary bone tumors yielded 11 lesions with features allowing classification as malignant fibrous histiocytoma on a purely histological basis. Correlation with roentgenograms and clinical data indicated that these tumors occurred as osteolytic lesions associated with a high incidence of pathologic fractures in the metaphyses of skeletally mature long bones. Nine patients developed pulmonary metastases and 3 developed lymph node metastases within 21 months following diagnosis. The average survival was 12 months in 6 of the 9 patients who had no secondary treatment in their metastases. Treatment of 3 patients with metastatic lesions with chemotherapy or radiotherapy has been clinically encouraging. Some evidence was obtained that either or both the histiocytic and fibroblastic component may metastasize. There is a need for biopsy of metastatic lesions and autopsy followup to more accurately assess the mode of spread and histologic type of the metastases.