Papillary meningioma.

Six cases of papillary meningioma are described. Five patients are still alive 2 months, and 2, 7, 8 and 14 years after the operation respectively. No metastases or recurrences have been noted. One patient died from an intercurrent disease 2 years after operation. In all cases the papillary pattern was associated with one of the typical well known forms of meningioma. One case showed histologic features of anaplasia, i.e.: local high cellularity accompanied by mitotic activity and pleiomorphism. Only one or two features suggestive of a higher growth dynamism were noted in the other cases. The mechanism of the papillary structures is discussed. Vasotropism and a feeble cohesion between the cellular perivascular "crowns" are thought to be responsible for the papillary pattern which should be interpreted as a secondary phenomenon. It appears likely that the papillary pattern of meningioma is not always an expression of anaplasia when no other clinical and histologic signs of malignancy are present.