CLEAR-CELL NEOPLASMS AND PSEUDONEOPLASTIC LESIONS OF THE CENTRAL-NERVOUS-SYSTEM

Mass lesions of the central nervous system (CNS) that may assume a cle ar cell appearance are diverse in nature. Primary conditions in this c ategory include oligodendroglioma, hemangioblastoma, germinoma (semino ma), clear cell and chordoid meningioma, pleomorphic xanthoastrocytoma , and lipid-rich glioblastoma. These proliferations usually can be ide ntified by attention to clinical presentation, topographic location, r adiographic details, and histological nuances. Occasionally, however, eletron microscopy or immunohistological analysis may be necessary. A recommended panel of reagents for the evaluation of clear cell primary CNS lesions include antibodies to glial fibrillary acidic proteins, S -100 protein, epithelial membrane antigen, vimentin, keratins, placent al-like alkaline phosphatase, and synaptophysin. This article reviews the salient clinicopathologic attributes of such proliferations, elabo rates a practical approach to their diagnosis, and discusses important differential diagnostic considerations. The latter include malformati ve lesions, infarcts, inflammatory conditions, and secondary lymphomas , carcinomas, and melanomas. Copyright (C) 1997 by W.B. Saunders Compa ny.