Benign intracranial cysts and certain congenital neoplasms

Highlights of histological, electron microscopic and immunohistochemical features of various benign intracranial cysts are reviewed. These include arachnoid, endodermal, ectodermal and colloid cysts of the third ventricle. Certain noteworthy morphological findings are enumerated in these benign congenital neoplasms. Focal necroses and endothelial proliferation and immunoreactivity for alpha B-crystallin in some of the giant cells are observed in subependymal giant cell astrocytomas. The fine structure of Alzheimer's neurofibrillary tangles is examined in meningoangiomatosis. An overview of dysembryoplastic neuroectodermal tumor a recently recognized new entity associated with intractable seizures in young patients is provided.