Abstract

Secretory meningioma is now a distinctive subtype of mostly meningotheliomatous type of meningioma, which was first defined by Alguacil-Garcia et al. It shows characteristic light-microscopic, ultrastructural, and immunohistochemical features of epithelial and secretory differentiation of meningothelial cells with accumulation of secretory material in the from of hyaline inclusions. A 38-year-old female presented with headache for about 5 months. Magnetic resonance imaging revealed a round multilobated mass, measuring 4x4x3 cm, in the right inferior frontal lobe near the skull base, with surrounding brain edema. Histologically, the tumor basically showed a pattern of meningotheliomatous meningioma but tended to deposit eosinophilic homogeneous material both in the intracellular and extracellular spaces. The shape was globular intracellularly and of variable shape and often conglomerated extracellularly. Histochemical stains revealed the material not of psammomatous but of pseudopsammomatous proteinaceous nature. On electron microscopy, there was no intracellular lumen with secretion but granular electron-dense material of variable size accumulated in the degenerated endoplasmic reticulums, suggestive of proteinaceous secretion.

• Keywords: Secretory meningioma;Meningothelial;Meningioma;Epithelial differentiation;Hyaline inclusion