Spinal low-grade neoplasms with extensive leptomeningeal dissemination in children.

Abstract

The aim of this study is to re-appraise paediatric leptomeningeal disseminated spinal low-grade neoplasms putting forward the hypothesis that these tumours may represent a possible distinctive clinico-pathological entity. Three children affected by these rare neoplasms are reported, 2 boys and 1 girl aged 40 months, 7 and 12 years respectively. Despite treatment, 2 died at 9 months and 9 years, while 1 has survived with stable disease at 24 months after diagnosis. Histologically, these tumours shared the generic histological appearance of low-grade neuroectodermal neoplasms, without any features that allowed them to be included in a specific classification niche. The magnetic resonance imaging of the leptomeningeal dissemination took the form of a thick, diffuse subarachnoidal enhancement involving the brain as well the spine in 2 patients; in 1 patient there was an extensive enhancement along the surface of the brain and of the spinal cord and multiple small cysts, creating the impression of a diffuse microcystic meningoencephalopathy. The patients described here and the similar ones found in the literature cannot be easily placed into the present WHO system of classification for central nervous system tumours.