Philip George Eye1, Laurence Davidson2, Patrick J Malafronte3, Sarah Cantrell4, Brett J Theeler5. 1. Walter Reed National Military Medical Center, Department of Neurology, United States. Electronic address: p.g.eye88@gmail.com. 2. Walter Reed National Military Medical Center, Department of Neurosurgery, United States. 3. Walter Reed National Military Medical Center, Department of Pathology and Laboratory Medicine, United States. 4. Walter Reed National Military Medical Center, Darnell Medical Library, United States. 5. Walter Reed National Military Medical Center, Department of Neurology, United States.
Abstract
BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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. Published by Elsevier B.V.
BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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. Published by Elsevier B.V.
Authors: Caleb P Wilson; Arpan R Chakraborty; Panayiotis E Pelargos; Helen H Shi; Camille K Milton; Sarah Sung; Tressie McCoy; Jo Elle Peterson; Chad A Glenn Journal: Neurooncol Adv Date: 2020-09-09
Authors: Annette Leibetseder; Johannes Leitner; Maximilian J Mair; Stephan Meckel; Johannes A Hainfellner; Martin Aichholzer; Georg Widhalm; Karin Dieckmann; Serge Weis; Julia Furtner; Tim von Oertzen; Matthias Preusser; Josef Pichler; Anna Sophie Berghoff Journal: J Neurol Date: 2021-08-03 Impact factor: 4.849