PIK3CA mutation in a mixed dysembryoplastic neuroepithelial tumor and rosette forming glioneuronal tumor, a case report and literature review.

Journal Article (Review;Journal Article)


Rosette forming glioneuronal tumors are rare, World Health Organization (WHO) grade I novel tumors frequently affecting the fourth ventricle or posterior fossa with typical neuronal pseudorosettes. RGNTs have been described as possessing additional histologic features of DNETs or pilocytic astrocytomas. Activating PIK3CA mutations have been identified as recurring genetic event in RGNTs.


We report a 35year old man who presented with binocular diplopia, headache, and was found to have a third ventricle tumor. Tumor pathology and oncogene evaluation were conducted.


The tumor demonstrated histologic features consistent with mixed RGNT/DNET. Genetic studies revealed a PIK3CA mutation in exon 9 (E545K, C. 1633G>A) without IDH1, p53, 1p19q chromosomal co-deletion, or BRAF mutations. A literature search revealed six cases of PIK3CA mutations in RGNTs and seven cases of mixed RGNT/DNET. No cases of mixed RGNT/DNET with a PIK3CA mutation have been described.


This is the first documented case of an RGNT/DNET with an activating PIK3CA mutation. The presence of a PIK3CA mutation aids histologic classification in the setting of mixed histology, and may have implications for targeting the PI3K/AKT/mTOR pathway in this tumor type.

Full Text

Duke Authors

Cited Authors

  • Eye, PG; Davidson, L; Malafronte, PJ; Cantrell, S; Theeler, BJ

Published Date

  • February 2017

Published In

Volume / Issue

  • 373 /

Start / End Page

  • 280 - 284

PubMed ID

  • 28131206

Electronic International Standard Serial Number (EISSN)

  • 1878-5883

International Standard Serial Number (ISSN)

  • 0022-510X

Digital Object Identifier (DOI)

  • 10.1016/j.jns.2016.11.003


  • eng