Hemangiopericytoma of meninges. II. General and clinical data.

Meningeal hemangiopericytoma (HP) has mostly been viewed as a variant of meningioma. There is more and more evidence, however, that HP constitutes a separate entity among tumors of the central nervous system. The data of intracranial and spinal HP of 17 of our patients and from a review of the literature is compared to meningioma and to peripheral HP. Meningeal and peripheral HP present with a similar sex ratio, age distribution, tendency to metastasize and are almost never multiple. This is fundamentally different from meningioma. Other data of meningeal HP like interval between first operation and manifestation of a recurrence or metastasis and survival time cannot be compared to peripheral HP due to its special location. Prognosis of meningeal HP is distinctly worse than of meningioma, placing HP between malignancy grade I and II as specified by WHO.