Meningioma associated with intraosseous lipoma.

Intraosseous lipomas of the skull are quite rare and only eight cases have been reported. The lipoma in our case was different from that in others in that it showed remarkable proliferation of collagen tissue. This is the first report of meningioma occurring after removal of an intraosseous lipoma of the skull. This report concerns a rare case of a 32-year-old female who developed a huge convexity meningioma 11 years after successful removal of intraosseous lipoma of the left frontoparietal bone. The meningioma originated from the convexity where the lipoma had been, and extended intracranially to the sphenoid ridge. The patient underwent surgical exploration showing that the meningioma had invaded the frontoparietal convexity bone and was firmly attached to the coronal suture with a large dural defect. This rare coincidence suggests that proliferative changes of the intraosseous lipoma and meningeal neoplasm may be the result of the same, as yet unknown, mechanism.