Diffuse leptomeningeal neuroepithelial tumor: 9 pediatric cases with chromosome 1p/19q deletion status and IDH1 (R132H) immunohistochemistry

Matthew J. Schniederjan*, Sarah Alghamdi, Amilcar Castellano-Sanchez, Claire Mazewski, Barunashish Brahma, Daniel J. Brat, Carole D. Brathwaite, Anna J. Janss

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

57 Scopus citations


Leptomeningeal dissemination in children is typical of high-grade, and occasionally low-grade, neoplasms. Rare cases of widely disseminated oligodendroglia-like leptomeningeal tumors, sometimes with associated spinal cord lesions, have been described that respond to treatment and follow an indolent course. Whether these lesions represent an established tumor category or are a unique entity remains to be established. We present 9 pediatric cases of such diffuse leptomeningeal neuroepithelial tumors (DLNT), 8 with assessment of 2 common genetic alterations seen in oligodendrogliomas, 1p and 19q chromosomal deletions and isocitrate dehydrogenase-1 (IDH1) R132H mutations. Four patients were male and 5 female, with a mean age at presentation of 4 years (range, 2 to 7 y). All presented with signs of increased intracranial pressure and diffuse contrast enhancement of the leptomeninges by magnetic resonance imaging. Three had a cervical or upper thoracic spinal cord tumor, and another had a small cerebellar lesion. Leptomeningeal biopsies showed a thickened and fibrotic arachnoid infiltrated by monotonous cells with round nuclei and prominent perinuclear clearing. All cases were strongly immunoreactive for S100 protein, and most showed faint granular synaptophysin reactivity. Six of 8 cases showed deletions of chromosome arm 1p by fluorescence in situ hybridization, 2 of which also had loss of 19q. None of the lesions reacted with IDH1-R132H antibodies. Although the clinicopathologic features show overlap of these DLNT lesions with oligodendroglioma and extraventricular neurocytoma, they do not exactly match either one, suggesting that DLNTs are a distinct tumor entity.

Original languageEnglish (US)
Pages (from-to)763-771
Number of pages9
JournalAmerican Journal of Surgical Pathology
Issue number5
StatePublished - May 2013


  • 1p
  • 1p19q
  • disseminated
  • glioneuronal
  • leptomeninges
  • neurocytoma
  • neuroepithelial
  • oligodendroglioma
  • pediatric
  • spinal cord

ASJC Scopus subject areas

  • Anatomy
  • Pathology and Forensic Medicine
  • Surgery


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