Diffuse leptomeningeal glioneuronal tumor with distinct neuronal and glial components but identical diagnostic molecular and genetic features.

Autor: Witten AJ; Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA., Dougherty C; MD Degree Program, Indiana University School of Medicine, Indianapolis, Indiana, USA., Hao C; Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Jazyk: angličtina
Zdroj: Neuropathology : official journal of the Japanese Society of Neuropathology [Neuropathology] 2024 Dec; Vol. 44 (6), pp. 440-444. Date of Electronic Publication: 2024 Jul 28.
DOI: 10.1111/neup.12996
Abstrakt: The 2021 World Health Organization (WHO) classification of the central nervous system (CNS) tumors has classified diffuse leptomeningeal glioneuronal tumor (DLGNT) as a mixed neuronal and glial tumor. Here, we report a DLGNT with two distinct morphological tumor components but identical molecular features. A four-year-old female child presented with progressive right upper extremity weakness. Magnetic resonance imaging (MRI) revealed the leptomeningeal enhancement over the brain stem and cervicothoracic spine. The histological examination of surgical specimens revealed two distinct tumor components: approximately half of the tumor is composed of oligodendroglioma-like tumor intermingled with nodules of ganglioglioma-like tumor. Immunohistochemistry confirmed the oligodendroglioma and ganglioglioma features. The molecular genetic studies demonstrated the features of DLGNT, including fusion of KIAA1549::BRAF, deletion of chromosome 1p, and absence of isocitrate dehydrogenase 1/2 (IDH1/2) mutation in both tumor components. Interestingly, the genetic studies also revealed the distinct chromosomal abnormalities of the loss of chromosome 4 only in oligodendroglioma-like tumor and copy neutral loss of heterozygosity of 7Q34Q36.3 in the ganglioglioma-like tumor component. This case highlights the critical role of molecular testing in the diagnosis of rare cases of DLGNT with diverse morphological components as well as in the identification of unique molecular alternations responsible for morphological phenotypes of the distinct tumors in DLGNT.
(© 2024 The Author(s). Neuropathology published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Neuropathology.)
Databáze: MEDLINE
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