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Washington University Experience | NEOPLASMS (MENINGIOMA) | Anaplastic | 20B2 Meningioma, WHO III & metaplasia (Case 20) H&E 2

20B2-6 This neoplasm is composed of tumor cells with generally round-to oval nuclei, coarsely speckled chromatin, often prominent nucleoli, and variably eosinophilic or relatively clear cytoplasm. The cells are arranged in sheets throughout much of the tumor, but also form large perivascular papillae. Mitotic figures are abundant, exceeding a density of 20/10HPF in many areas. Geographic necrosis, occasionally with pseudopalisading, is widespread. Invasion of soft tissue and bone are noted with resultant hyperostosis.

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