Primary intraosseous malignant meningioma of the skull: case report.

Primary intraosseous meningioma of the skull is rare. This report describes a 61-year-old man who was treated by craniectomy 3 times for a repeatedly recurrent primary intraosseous malignant meningioma. Transmission electron microscopy revealed interdigitation of cytoplasmic processes, microfilaments, and distinct desmosomal structures. Immunocytochemical studies of cultured cells showed strong expression of vimentin and weakly positive staining for S-100 protein. Primary intraosseous malignant meningioma should be considered in the differential diagnosis of massive solitary osteolytic lesions of the skull.