Secretory meningiomas: clinical and immunohistochemical observations

Secretory meningiomas are a rare histological subtype of these benign intracranial tumors. Few reports have been published regarding their tendency to develop peritumoral edema.

Between July 1994 and February 1999, 11 patients with secretory meningiomas underwent operations in the Department of Neurosurgery, University of Kiel, Kiel, Germany. The clinical notes and radiological data (computed tomographic and magnetic resonance imaging scans) were reviewed. Immunohistochemistry was used to examine the expression of carcinoembryonic antigen and epithelial membrane antigen as well as progesterone and estrogen receptors.

Secretory meningiomas were found in 11 (5%) of 214 patients with intracranial meningiomas who were operated on in that period. All 11 patients were women. These patients' mean age was 65 years (range, 51-87 yr). The localization of these tumors was at the convexity in seven patients, at the sphenoid ridge in two patients, and in the olfactory groove and petroclival region in one patient each. Two meningiomas had no edema surrounding them, two meningiomas had a small amount of edema, two had moderate edema, and five had severe edema. No recurrences were observed during the mean follow-up period of 26 months (range, 8-65 mo). Immunohistochemically, all tumors contained pseudopsammoma bodies and reacted with epithelial membrane antigen and carcinoembryonic antigen. The MIB-1 antibody staining index showed a mean of 2% (range, 0-7%).

Secretory meningiomas are rare tumors, and they are mainly localized at the frontal convexity and the sphenoid ridge. They are surrounded by more edema than usual. The preponderance of female patients with this presentation is striking. The expression of carcinoembryonic antigen and epithelial membrane antigen is a characteristic feature of secretory meningiomas. These meningiomas are also positive for progesterone receptors, which has been shown to be a good prognostic factor.