Papillary meningioma

The recognition of a papillary meningioma in other than the dural locations characteristic of meningioma is difficult. Papillary meningiomas resemble papillary ependymomas, choroid plexus papillomas, and carcinomas.One should look for a high ratio of vimentin to CK and absence of GFAP to identify the meningioma. 

Fits into a well-differentiated subtype (text) (WHO grade II is assigned to clear cell and chordold meningiomas) (WHO grade III is assigned to rhabdoid and papillary meningiomas)... 

Fibrillary MXPE may be confused with fibrous meningioma and schwannoma. The epithelial and papillary variants may resemble carcinoma or meningioma. A positive GFAP stain response differentiates the MXPE from GFAP-negative carcinoma and meningioma. MXPE lacks type FV collagen and fibronectin-positive basement membranes around each cell, which is a feature of schwannoma (Fig. 20.24A). 

Papillary configurations in meningiomas are associated with high rates of local recurrence and metasta-ses. The papillae have a CD31-positive vascular core. 

Psammoma bodies = laminated calcifications that occur in > meningiomas and papillary carcinomas of the thyroid and... 

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