Hypercellular meningothelial neoplasm. The tumor exhibits a predominant solid, sheet-like growth pattern, with areas lacking classic whorled architecture. The neoplastic cells shows syncytial cytoplasm and demonstrate marked cytologic atypia, including nuclear pleomorphism, hyperchromasia, and increased nuclear-to-cytoplasmic ratio, and prominent macronucleoli with frequent areas exhibiting small cell morphology. Mitotic activity is readily identified. Foci of glial tissue infiltrated by the tumor are observed. There is no evidence of spontaneous coagulative tumor necrosis in the examined tissue.
Picture is that of Atypical meningioma, WHO grade 2, with brain invasion.
Immunostaining was done with appropriate positive and negative controls and revealed positive reaction to EMA and PR, whereas negative to GFAP. Ki-67 labeling index is about 15%.
Extra-axial, dural-based paramidline lesion at the high left parietal region abutting the superior sagittal sinus with surrounding vasogenic edema, radiologically suggestive of an atypical vertex meningioma
Soft tissue fragments collectively measured 3.5x3x1 cm, totally embedded.
Left parietal region extra-axial dural-based mass, total excision: