Elastosis in meningioma. A case report and electron microscopic study.

A 55-year-old man underwent left frontoparietal craniotomy for total removal of a parasagittal meningioma. The tumor showed a predominant pattern of meningotheliomatous meningioma and a partial pattern of angiomatous, transitional and fibrous meningioma. A striking feature was the appearance of unusually numerous elastinophilic material in the intercellular stroma. We observed a process in which the progress of elastosis changed the appearance of meningotheliomatous meningioma to a hypocellular, and subsequently acellular fibroelastotic node. Three years after the first craniotomy, meningioma recurred at the same site. The recurrent tumor also showed the histological pattern of meningotheliomatous meningioma with stromal elastosis, as previously observed. This is the first report of a case of meningioma with stromal elastosis. The present case represents the first unequivocal demonstration of elastogenesis in meningioma.