Spinal low-grade neoplasms with extensive leptomeningeal dissemination in children

Objective: 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. Case report: Three children affected by these rare neoplasms are reported, 2 boys and 1 girl aged 40 months, 7 and 12 years respectively. Results: 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. Discussion: 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.