Granular cell variant of meningioma: a case report and review of the literature.

We describe a diagnostically challenging case of granular cell variant of meningioma. The tumor was observed in the temporal and parietal lobes of the right cerebrum. Microscopically, neoplastic cells with granular and eosinophilic cytoplasm were round, polygonal, or spindled with no apparent mitosis or atypia. Immunohistochemistry showed the neoplasm arose from meninges, cytoplasmic granules were positive for periodic acid-Schiff (PAS) staining, and electron microscopy showed abundant mitochondria in the cytoplasm. Therefore, we made the diagnosis of granular cell variant of meningioma after excluding the differential diagnoses through morphologic, immunohistochemical, special staining, and ultrastructural examination.