Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Case Reports
. 2020 Jun 30;8(1):95.
doi: 10.1186/s40478-020-00978-7.

Diffuse leptomeningeal glioneuronal tumor: a double misnomer? A report of two cases

Romain Appay  1   2 , Mélanie Pages  3   4   5   6   7 , Carole Colin  2 , David T W Jones  8   9 , Pascale Varlet  3   4   10 , Dominique Figarella-Branger  11   12
Affiliations
Case Reports

Diffuse leptomeningeal glioneuronal tumor: a double misnomer? A report of two cases

Romain Appay et al. Acta Neuropathol Commun. .

Abstract

Diffuse leptomeningeal glioneuronal tumor (DLGNT) was introduced, for the first time, as a provisional entity in the 2016 WHO classification of central nervous system tumors. DLGNT mainly occur in children and characterized by a widespread leptomeningeal growth occasionally associated with intraspinal tumor nodules, an oligodendroglial-like cytology, glioneuronal differentiation and MAP-Kinase activation associated with either solitary 1p deletion or 1p/19q codeletion in the absence of IDH mutation.We report here two unexpected DLGNTs adult cases, characterized by a unique supratentorial circumscribed intraparenchymal tumor without leptomeningeal involvement in spite of long follow-up. In both cases, the diagnosis of DLGNT was made after DNA-methylation profiling which demonstrated that one case belonged to the DLGNT class whereas the other remained not classifiable but showed on CNV the characteristic genetic findings recorded in DLGNT. Both cases harbored 1p/19q codeletion associated with KIAA1549:BRAF fusion in one case and with BRAF V600E and PIK3CA E545A mutations, in the other.Our study enlarges the clinical and molecular spectrum of DLGNTs, and points out that the terminology of DLGNTs is not fully appropriate since some cases could have neither diffuse growth nor leptomeningeal dissemination. This suggests that DLGNTs encompass a wide spectrum of tumors that has yet to be fully clarified.

Keywords: Adult; BRAFV600E mutation; DLGNT; DNA-methylation profiling; Supratentorial.

PubMed Disclaimer

Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Fig. 1
Fig. 1
a MRI disclosed a nodule enhanced after gadolinium injection, located within the intraoperative cavity. b High cellularity neoplasm composed of relatively monomorphic oligodendrocyte-like cells associated with endocrinoïd vasculature. c KI67 labeling index was around 10%. d, e, f Tumor cells strongly expressed OLIG2 and synaptophysin and BRAFV600E. g Copy-number profile derived from DNA-methylation arrays revealed 1p/19q codeletion with additional gains of chromosomes 3 and 7
Fig. 2
Fig. 2
a, b MRI showed a cystic tumor with a mural nodule enhanced after gadolinium injection. c A proliferation of oligodendrocyte-like cells associated with a rich and branched vasculature. d Well demarcation of the tumor from the adjacent cortex. e, f The tumor cells strongly expressed OLIG2 and synaptophysin. g Copy-number profile derived from DNA methylation arrays revealed 1p/19q codeletion and KIAA1549:BRAF fusion
Fig. 3
Fig. 3
t-SNE plot of the 2 reported cases associated with 156 reference gliomas. Reference classes: AAP, anaplastic astrocytoma with piloid features; DLGNT, diffuse leptomeningeal glioneuronal tumor; GG, ganglioglioma; LGm6-GBM [14]; NORM_HEMI, normal hemisphere; PA-Like [14]; PA_INF, posterior fossa pilocytic astrocytoma and PLNTY, polymorphous low-grade neuroepithelial tumor of the young
See this image and copyright information in PMC

References

    1. Louis DN, Perry A, Reifenberger G, von Deimling A, Figarella-Branger D, Cavenee WK, Ohgaki H, Wiestler OD, Kleihues P, Ellison DWT. World Health Organization classification of tumors of the central nervous system: a summary. Acta Neuropathol. 2016;2016(131):803–820. doi: 10.1007/s00401-016-1545-1. - DOI - PubMed
    1. Gardiman MP, Fassan M, Orvieto E, D'Avella D, Denaro L, Calderone M, Severino M, Scarsello G, Viscardi E, Perilongo G. Diffuse leptomeningeal glioneuronal tumors: a new entity? Brain Pathol. 2010;20:361–366. doi: 10.1111/j.1750-3639.2009.00285.x. - DOI - PMC - PubMed
    1. Agamanolis DP, Katsetos CD, Klonk CJ, Bartkowski HM, Ganapathy S, Staugaitis SM, Kuerbitz SJ, Patton DF, Talaizadeh A, Cohen BH. An unusual form of superficially disseminated glioma in children: report of 3 cases. J Child Neurol. 2012;27:727–733. doi: 10.1177/0883073811426500. - DOI - PubMed
    1. Deng MY, Sill M, Chiang J, Schittenhelm J, Ebinger M, Schuhmann MU, Monoranu CM, Milde T, Wittmann A, Hartmann C, et al. Molecularly defined diffuse leptomeningeal glioneuronal tumor (DLGNT) comprises two subgroups with distinct clinical and genetic features. Acta Neuropathol. 2018;136:239–253. doi: 10.1007/s00401-018-1865-4. - DOI - PubMed
    1. Rodriguez FJ, Perry A, Rosenblum MK, Krawitz S, Cohen KJ, Lin D, Mosier S, Lin MT, Eberhart CG, Burger PC. Disseminated oligodendroglial-like leptomeningeal tumor of childhood: a distinctive clinicopathologic entity. Acta Neuropathol. 2012;124:627–641. doi: 10.1007/s00401-012-1037-x. - DOI - PubMed

Publication types

Substances