Abstract 1- 0900-0915
Category: Clinical

At the end of the session,
participants will be able to:

  1. Identify the presence of this molecular alteration in low grade gliomas
  2. Use this important information to correlate it with clinical implications
Presenter

My name is Francesca Gianno and I’m a pathologist. I studied at Sapienza University, in Rome, and after the specialty in Anatomical Pathology, I attended the doctoral course in molecular medicine. I always got interest for pediatric brain tumors. During the whole period of my training, I had the possibility to deepen the research on these tumors thanks to the Italian National Program of Centralization of Paediatric Brain Tumours. On July 2021 I started my neuropathology fellowship at SikKids Hospital.

Authors

Francesca Gianno 1, Jennifer A. Chan 2, Phedias Diamandis 3,4, John A. Maguire 5, Qi Zhang 6 Cynthia Hawkins 1, Lili-Naz Hazrati 1

1 Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada; Department of Pathology, The Hospital for Sick Children, Toronto, ON, Canada 2 University of Calgary, Calgary, Canada 3 Princess Margaret Cancer Centre/Laboratory Medicine Program, University Health Network, Toronto, Ontario, Canada. 4 Departments of Laboratory Medicine and Pathobiology and Medical Biophysics, University of Toronto, Toronto, Ontario, Canada 5 Department of Pathology & Laboratory Medicine, Costal Health-Vancouver General Hospital 6 Department of Pathology, London Health Sciences Centre

 

Target Audience:
Pathologists, Residents, Medical Students, Clinicians

CanMEDS:
Medical Expert (the integrating role), Communicator, Collaborator, Professional

Histologic and clinical spectrum of brain tumours harbouring FGFR3-TACC3 fusions

Abstract

Fibroblast growth factor receptor (FGFR) gene family alterations, including point mutations and fusions, have been described in brain tumours as oncogenic drivers (NG 2013; 45(6): 602–612). FGFR3-TACC3 fusions were initially described in IDH wildtype glioblastomas (Science 2012; 337:1231–1235) and are most frequently seen in morphologic or molecular GBM although occasional WHO grade 2 astrocytomas may harbour this alteration. The significance of this alteration as a single driver in low grade glioma is unclear. In order to better understand the clinical implications of finding this alteration, a series of low-grade gliomas underwent molecular testing at SickKids. The series includes six samples of diffuse low-grade gliomas, with a mean age of 24.8 years (range 1 to 44 years), three males and three females. Five out six tumours are localized in the supratentorial region, and one in the spinal cord. Three patients presented with seizures, one was asymptomatic. Morphologic appearance showed different aspects, from cells with oligo-like features in a neuropil-rich stroma to spindle cells with fibrillary cytoplasm in a loose microcystic background. Single nucleotide polymorphism (SNP) array was performed on two samples and one of them shows the gain of chromosome 7 and loss of chromosome 10, indicating a molecular profile of high grade glioma. Follow-up was available for four patients, all are alive without progressive disease with follow-up ranging from six months to two years. Longer follow-up will be required to determine the significance of this alteration in low grade glioma.