Primary malignant fibrous histiocytoma (fibrous xanthoma) of bone

The probable histiocytic origin of a group of benign and malignant tumors known as histiocytomas or fibrous xanthomas appears to be well established and is based on a combination of conventional light microscopy, tissue culture and ultrastructural studies. Our experience with 23 cases of primary malignant fibrous histiocytoma of bone is presented, together with a review of additional cases documented in the literature. Particular emphasis has been placed on the radiologic aspects of primary malignant fibrous histiocytoma of bone, together with a brief review of its clinical and histologic features. The fact that the skeleton can be involved de novo rather than by direct extension from neighboring soft tissue tumors or by metastatic spread is a relatively new concept.