Meningioma

72-year-old female with right frontal lobe tumor.

Procedure: Resection of right frontal lobe tumor.

Gross: The specimen consists of multiple hemorrhagic irregular tissue fragments measuring 0.7

Focal tumor necrosis and rare pleomorphic nuclei. Rare mitotic figures are noted, with the Ki-67 <1%. EMA is positive.

The EMA stain is focally positive. The Ki-67 stain shows a low proliferative rate (<1%).

This meningioma infiltrates the dura mater extensively. There is nuclear pleomorphism and rare mitotic figures. There is no necrosis.

The tumor is diffusely strongly positive for vimentin and focally positive for epithelial membrane antigen (EMA), mainly in the microcystic areas.

The tumor has dense cellularity, focal necrosis and mitotic rate up to 10/10 HPF, with focal areas exhibiting even higher mitotic counts. Nuclei are enlarged and nucleoli are frequent and prominent.