Subependymal giant cell astrocytoma (SEGA): Is it an astrocytoma? Morphological, immunohistochemical and ultrastructural study

Abstract

Calcifications were observed in six cases (66%). By immunohistochemistry, the majority of the tumors were GFAP-(9; 100%), neurofilament-(8, 89%), neuron-specific enolase-(9, 100%), and synaptophysin-(8; 89%) positive. Ultrastructural studies were performed on four cases. In all four there were glial cell processes filled with intermediate filaments. In one case dense core putative neurosecretory granules were appreciable. Our results emphasize the glioneuronal nature of SEGA. We suggest moving it into the group of mixed glio-neuronal tumors under the denomination of subependymal giant cell tumor.

Clinical and imaging features of subependymal giant cell astrocytoma: report of 20 cases

“…Clinical presentation SEGA is a WHO Grade I tumor that often occurs in the lateral ventricle near the foramen of Monro and rarely in the third ventricle, the fourth ventricle and pineal region [1][2][3]. However, the outcome of SEGA may be poor due to obstructive hydrocephalus or intratumoral hemorrhage [4].…”

“…Subependymal giant cell astrocytoma (SEGA) is a World Health Organization (WHO) Grade I tumor that typically occurs in the lateral ventricle near the foramen of Monro and rarely in the third ventricle [1]. Nevertheless, their outcome may be poor due to obstructive hydrocephalus or intratumoral hemorrhage [2].…”

Erk activation as a possible mechanism of transformation of subependymal nodule into subependymal giant cell astrocytoma

“…The giant cells are similar to those in cortical tubers. Also some foci of necrosis can be present, as well as some mitotic figures; the labeling index of Ki-67 is about 1% [1,2,4], although rare cases of higher mitotic index are also reported [3].…”

Capacidade proliferativa in vitro de precursores neuro-gliais, telencefálicos e expressão dos genes 1 e 2 do Complexo da Esclerose Tuberosa (TSC1 e TSC2)

“…Associados às tuberosidades corticais ou isoladamente, podem-se observar três tipos de lesões: (i) nódulos subependimários (SENs); (ii) astrocitomas subependimários de células gigantes (SEGAs); e (iii) linhas de migração neuronal na substância branca subcortical que sugerem heterotopias neuronais (Gómez et al, 1999;DiMario et al, 2004 (Buccoliero et al, 2009). …”

“…SEN e SEGA expressam a proteína 4 mediadora da resposta da colapsina (CRMP4) e doublecortina, marcadores da zona subventricular (Seung-Ki et al, 2001, Lee et al, 2003Chan et al, 2004;Ess et al, 2004;Buccoliero et al, 2009). Em conjunto, esses dados sugerem que SEN e SEGA sejam decorrentes de defeitos de diferenciação celular (positividade para marcadores neurais e gliais) e derivados de precursores neurogliais, subventriculares (Crino et al, 1996).…”