A case of malignant fibrous histiocytoma (MFH) in the skull bone presenting extensive permeative osteolysis.

Malignant fibrous histiocytoma (MFH) of the skull is rare. This case showed an extremely unusual growth pattern for MFH. The radiographs and magnetic resonance imaging (MRI) demonstrated an osteolytic growth pattern in the skull base and temporal bone, without forming a mass lesion. We considered the possibility of a malignant tumor with a myxoid component based on its growth pattern and MRI intensity. Pathological examination revealed dense proliferation of the neoplastic spindle cells with storiform pattern and focal myxoid or fibrotic areas. Only one other case of MFH with myxoid change of the skull bone has been documented in the English literature.