Intra- and Extraosseous Malignant Histiocytoma (Malignant Fibrous Xanthoma)

Twenty cases of malignant histiocytoma with skeletal involvement were analyzed, and the clinical, radiological, and pathological findings in this entity were investigated, with emphasis on lesions which primarily or secondarily affect bone. These studies showed that malignant histiocytoma or fibrous xanthoma, although known by a confusing variety of labels, is a neoplastic entity of histiocytic origin distinct from the histiocytosis “X” family of lesions and the classic xanthomatoses.