Primary chemotherapy in malignant fibrous histiocytoma of bone — Updated UTMD Anderson Cancer Center Experience

Abstract

Malignant Fibrous Histiocytoma (MFH) of bone is a relatively recently recognized entity. After the initial reports in the early 70 s [1], this entity became well established in the pathology and clinical literature by the late 70 s [2–4]. The age distribution is variable, patients are generally older than those with osteosarcoma, and there seems to be a slight predilection for males [5]. The skeletal distribution is also variable, with a predilection for the metaphyses of long bones [6]. Radiologically, it manifests as an aggressive radiolucent defect with ill-defined margins and often, an associated soft-tissue mass. Histologically, it shows striking resemblance to MFH arising in soft tissues. Not infrequently, it constitutes the high grade component of a de-differentiated chondrosarcoma, which has a relatively poorer prognosis. It often is a component of osteosarcomas, and histologically, the only major difference between a fibroblastic osteosarcoma and an MFH is the presence or absence of osteoid. In our experience at the UT MD Anderson Cancer Center, we have seen 2 patients, 1 of them reported in this series, where the initial biopsy and the final surgical specimen diagnosis was felt to be an MFH, but the metastatic disease that developed at a later date unequivocally demonstrated osteoid, making us hypothesise, that MFH of bone may indeed be a variant of fibroblastic osteosarcoma with no demonstrable osteoid initially, however it can manifest at a later date.