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Washington University Experience | NEOPLASMS (MENINGIOMA) | Meningioma - Clear cell | 21D2 Clear cell meningioma (Case 21) PASD 40X
Loss of tumor cell PAS staining with diastase identifies the stored material as intracytoplasmic glycogen. (PAS-D) ---- Ancillary data (not shown): The tumor is strongly and diffusely immunoreactive for vimentin. There is focal EMA and focal rare nuclear immunostaining for PR (less than 1%). The tumor is negative for cytokeratin, synaptophysin, S-100 protein, placental alkaline phosphatase (PLAP), and CD34. ----
FISH studies showed deletions of both 1p and 14q. There was also evidence for polysomy (i.e. gain) of chromosome 18 and normal dosages of chromosome 22q. Although this pattern is not entirely specific, deletions of both chromosomes 1p and 14q are common in high grade meningiomas and therefore, this genetic pattern further supports the diagnosis of anaplastic meningioma. ---- The morphologic and immunohistochemical features are consistent with a diagnosis of anaplastic meningioma with focal brain invasion and clear cell features, WHO Grade 3.
