Benign intrinsic tectal “tumors” in children

Abstract

A specific group of intrinsic dorsal midbrain tumors was identified in six children by computerized tomography (CT) and magnetic resonance (MR) imaging. Each patient presented with raised intracranial pressure as a result of hydrocephalus due to obstruction of the sylvian aqueduct. No patient had brain-stem signs referable to the tectal tumor initially or subsequently. All six children underwent cerebrospinal fluid (CSF) diversionary procedures. The radiological features were consistent and specific, with all patients showing tectal calcification or primary increased attenuation of the tectal plate on CT scans. In addition, lack of contrast enhancement was noted initially in four patients and eventually in all six patients. In all patients MR imaging showed a focal tectal tumor distorting the collicular plate with no cystic component and increased signal intensity on T2-weighted images. There has been no evidence of progression in these six patients in the follow-up period ranging from 8 months to 17 years (8 months and 2 1/2, 4 1/2, 8, and 17 years). Diversion of CSF has been the only surgical treatment and no patient underwent deep x-ray therapy. Five patients have had normal intellectual development. In contrast to the majority of previously described periaqueductal and tectal tumors, this group of lesions appeared to be truly benign. The authors suggest that patients presenting with these clinical and radiological features may be managed by CSF diversion, serial examination, and MR imaging.

Pediatric tectal plate gliomas: clinical and radiological progression, MR imaging characteristics, and management of hydrocephalus

“…4,7,8,13 Magnetic resonance imaging demonstrates a focal, well-circumscribed, bulbous lesion deforming the quadrigeminal plate above the cerebral aqueduct that may have a posterior exophytic component that extends beyond the tectal plate. 3,4 The histopathology is commonly benign and includes nonneoplastic hamartoma 11,21 as well as lowgrade astrocytomas such pilocytic 2,14,16 and nonpilocytic astrocytomas, 5,14,20,22 mixed gliomas, 14 and rarely more aggressive tumors such as anaplastic astrocytomas.…”

Tectal plate tumors

“…In fact this was later discovered as not tru e . Many papers have oriented the presence of this tumor as a special site of low grade gliomas [4][5][6]9,10,18 . These tumors appear to present a better pro g n o s i s given to a slow growing rate and boundaries displacement instead of an infiltrative behaviour.…”

Tumores intrínsecos benignos da região tectal: considerações a propósito de dois casos

“…Tumores intrínsecos do tronco encefálico representam 10 a 20% de todas as neoplasias da infância 3,8,9 e seu prognóstico é considerado desanimador, com a maioria dos pacientes morrendo em média dois anos após o diagnóstico 4,9 . A introdução de métodos de imagem mais sofisticados, como a tomografia computadorizada (TC) e a ressonância nuclear magnética (RNM), veio demonstrar que os tumores do tronco encefálico estão longe de constituir grupo homogêneo em relação a seus aspectos clínicos, patológicos e biológicos, permitindo identificar subgrupos diferentes da forma clássica, difusa e infiltrativa 3 * 5,8,14,15 . Como consequência, estratégias de tratamento mais racionais puderam ser elaboradas, permitindo a abordagem cirúrgica de algumas lesões e alterando significativamente o prognóstico de certos pacientes 3 5 1 4 1 5 .…”

“…A definição destes subgrupos demonstrou também, que o seu prognóstico é influenciado pelo tipo do tumor e pela sua localização 3 * 5 , 8 , 9 , 1 4 1 5 . Um subgrupo de tumores focais, localizados no tectum mesencefálico, foi recentemente identificado 1,8 , merecendo registro devido à sua peculiar forma de apresentação e características evolutivas. Relatamos dois desses casos.…”