9/27/2005 Case 1: Atypical meningioma

Clinical History:

A 63 year old man with a dural-based neoplasm. The slide showed a meningioma with cells with prominent nucleoli, easily seen mitotic figures, but no other unusual features or patterns. There was no demonstrable brain invasion and there was no necrosis.

Diagnostic Notes:

Discussion centered around whether to diagnose this as an Atypical Meningioma or as a Malignant ("Anaplastic") Meningioma. There were differing counts of the mitotic index, but most of those present felt that the tumor, while clearly at least Atypical, did not meet the threshold for a diagnosis as malignant or anaplastic. Opinions were offered that without a frankly sarcomatous component, or papillary patterns, or possibly rhabdoid or clear cell patterns, a diagnosis of malignant meningioma should not be made. Others stated that the published statistics on meningiomas with very high mitotic rates showed that these were malignancies. Dr Arie Perry's name was invoked by both sides of the argument. Officially the case was signed out as Atypical Meningioma, not Malignant Meningioma.

Slide Image:

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