[A clinico-pathologic study of primary malignant fibrous histiocytoma of bone].

Primary malignant fibrous histiocytoma of bone (PBMFH) is a rare tumor. In this series 11 cases of PBMFH (7 men, 4 women, mean age 39.6 years, range 15-62) were reported. They were studied by using morphology, immuno-histochemistry combined with the relevant clinical materials. It showed that most of the patients complained of local pain as the first symptom, and it generally arose in proximal or distal end of extremities. Roentgenographically, it mainly displayed a lytic destruction of bone. Like soft tissue malignant fibrous histiocytoma, it was composed of a mixture of plump fibroblast-like cells and large round or polymorphic histiocyte-like cells and usually showed a storiform pattern. But there were no myxoid and inflammatory subtypes encountered in these cases, except the storiform-pleomorphic type (9 cases) and giant cell type (2 cases). So it appears to have some difference between the subtypes of MFH of bone and soft tissue. Since the histomorphology and immunohistochemical reaction are less characteristic, especially with the morphological pleomorphism and marked cellular heterogeneity, diagnosis of PBMFH must depend on multifacet observation and comprehensive assessment.