Sekretuar Meningiom: Radyolojik ve Patolojik Olarak Malign Tümörlerle Karıştırılabilen Nadir Bir Antite

Abstract

AbstractMeningiomas are slow growing, extra axial brain tumors that originating from the meningothelial cells of the arachnoid. Meningiomas are the most common brain tumors, however secretory meningiomas are extremely rare variant and can be confused radiologically and pathologically with malignant tumors. A 48 years old male was presented with a complaint of headache and visual impairment in the left eye. Magnetic resonance imaging revealed an extra axial mass lesion in the left pontocerebellar region, 57x48x30 mm in size, and marked edema around the mass. Microscopically, a tumoral lesion consisting ofuniform meningothelial cells with oval-round nuclei, thin vesiculated chromatin, and moderately eosinophilic cytoplasm was observed. The presence of epithelial differentiation characterized by pseudopsammom structures formed by lumens containing eosinophilic secretion was appointed among the tumor cells. Eosinophilic secretion within the lumens were highlighted with histochemical periodic acid schiff (PAS) stain. Immunoreaction was observed in the pseudopsammom structures and the surrounding tumor cells with carcinoembryonic antigen (CEA), epithelial membrane antigen (EMA) and pan cytokeratin (Pan-CK). Tumor cells were immunopositive with Vimentin and progesterone receptor (PR). Ki67 proliferation index was determined as <1%. No necrosis or mitosis were detected. The tumor was reported as ‘‘secretory meningioma’’. No additional treatment was applied to the case and no recurrence was detected in 32 month follow-up after surgical resection. Although secretory meningiomas are not clinically important due to their benign course, differantial diagnosis is critical, since they can be confused with malign tumors because of marked brain edema radiologically, elevated serum CEA levels and epithelial differentiation.