Mast cell-rich convexity meningioma presenting as chronic subdural hematoma: case report and review of the literature.

A 47-year-old woman with a convexity meningioma presenting as a chronic subdural hematoma is reported. This case is unique in that the symptoms were cyclical and stereotypic. The tumor contained an unusually high number of mast cells. A possible etiologic role of histamine-related vasodilation and tumoral hemorrhage is explored. The relationship between meningioma and subdural hematoma is discussed, and the literature is reviewed.