Intradiploic meningioma with inward and outward extensions in a rheumatoid arthritis patient

Background: meningiomas usually arise from clusters of arachnoidal cap cells. originating of a meningioma in an intraosseous region is rare condition. there are several theories about occurrence of these types of meningiomas. here we report a case of an intradiploic meningioma in a rheumatoid arthritis patient and discuss the mechanism of developing intraosseous meningiomas,differential diagnosis of intraosseous lesions of calvarium,relations of rheumatoid arthritis and extensions of meningioma outside the diploe. case description: a sixty three-year-old female patient who had been under the treatment for rheumatoid arthritis was admitted to the hospital with a swelling around her right eye. bony window of preoperative ct showed an expansile right sphenoid bone lesion. the mass was excised with internal and external tables of the temporal bone by craniectomy. conclusion: we advocate a wide resection,followed by cranioplasty with acrylic. if the subtotal resection is possible,residual lesion should be followed for adjuvant radiation therapy.