title: The fine structure of ependymomas.
abstract: Electron microscopy is a useful diagnostic technique in order to confirm or establish a definitive diagnosis in brain tumors that may have an atypical histological pattern, which requires a concrete diagnosis. In ependymomas, electron microscopy reveals morphological characters that have a pathognomonic diagnostic value, therefore allowing a definitive diagnosis. The main fine structural criteria of ependymomas consist of the numerous microvilli and cilia, which are incorporated in the cell body or extended freely in the intracellular space; the centriole or blepharoplast, which is located in the basis of the cilia; the large number of the fragmented microtubules in the perikaryon and the cellular processes (any small cellular projection into the neutrophil or intracellular space); the junctional apparatus between the cells, such as zonula adherens, zonula occludens and puncta adherentia; the basement membrane-like structure, seen in papillary ependymomas and ependymomas of the filum terminale; and the elongated cells in the loose intracellular space, commonly seen in myxopapillary ependymomas.
authors: Aristotelian University Department of Neurology, Thessaloniki & Research Institute for Alzheimer's disease, Iraklion Langada, Greece. sibh844@otenet.gr.
authors: Stavros J
authors: SJ
authors: Baloyannis
authors: Ioannis S
authors: IS
authors: Baloyannis
mesh_terms: D001921:Brain / Q000473:pathology* / Q000648:ultrastructure*; D002420:Cauda Equina / Q000473:pathology / Q000648:ultrastructure; D016543:Central Nervous System Neoplasms / Q000473:pathology*; D002923:Cilia / Q000473:pathology / Q000648:ultrastructure; D004806:Ependymoma / Q000473:pathology*; D006801:Humans; D008854:Microscopy, Electron; D008870:Microtubules / Q000378:metabolism / Q000648:ultrastructure