An immunohistochemical study of glial and neuronal markers in primary neoplasms of the central nervous system.

Paraffin-embedded tissues from 56 primary neoplasms of the central nervous system and seven cases of non-neoplastic reactive astrocytosis were examined by immunoperoxidase techniques on serial sections using monoclonal antibodies to glial fibrillary acidic protein (GFAP) and the 68 kDa neurofilament subunit and monospecific polyclonal antibodies to alpha- and gamma-enolase. gamma-Enolase was present in all neoplasms of neuronal origin, but was also present in anaplastic gliomas (particularly in giant cells), in some well-differentiated astrocytomas and reactive astrocytes. The cells containing gamma-enolase in these cases appeared morphologically identical to those containing alpha-enolase and GFAP in adjacent serial sections. No relationship was found between gamma-enolase immunoreactivity and cellular anaplasia in the gliomas studied. Subependymal neoplasms from patients with tuberose sclerosis exhibited evidence of both astrocytic and neuronal differentiation, sometimes in morphologically distinct cell populations, consistent with their suggested origin from a primitive cell line.