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Washington University Experience | NEOPLASMS (MENINGIOMA) | Brain Invasion | 7A1 Meningioma, atypical w brain invasion (Case 7) H&E 1

Case 7 History ---- The patient was a 66 year old woman with recent memory loss. MRI studies showed a 5.3 x 3.3 cm homogeneously-enhancing extra axial mass in the left frontal region, with a dural tail on each side and moderate vasogenic edema in the adjacent white matter. Operative procedure: Craniotomy with resection of tumor.---- 7A1,2 The tumor is a hypercellular meningioma composed predominantly of fascicles and whorls of spindled-cells with eosinophilic cytoplasm, ovoid nuclei, and occasional intranuclear cytoplasmic pseudo-inclusions. In many areas, the neoplastic cells show small cell change, spontaneous necrosis, macronucleoli and mitoses (<4/10HPF). Unmistakable brain invasion is identified as well as involvement of bone. These histological findings support the diagnosis of atypical meningioma with brain invasion, WHO grade 2. ---- Comment: Although brain invasion has historically has been regarded as a sign of malignancy, careful studies have demonstrated that brain invasive meningiomas consist of tumors which would otherwise be considered benign; such atypical tumors show recurrence and mortality rates that are virtually identical to those of atypical meningioma, WHO grade 2.

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