Abstract #6

by | Sep 19, 2022 | 2022 Abstracts

Abstract 6- 0830-0845
Category: Clinical

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

  1. Morphology may offer clues for certain molecular profile of glioblastoma.
  2. FGFR-TACC3 fusion is seen in a small subset of glioblastoma with specific clinicopathologic characteristics.
  3. If the tumor is negative for TERT promoter mutation and other molecular feature of glioblastoma, methylation profiling may
    be necessary for definitive diagnosis.

COI Disclosure:

None to disclose

Presenter

I am a diplomate of the American Board of Pathology and fellow of Royal College of Physicians of Canada in both anatomical pathology and neuropathology. Currently I am working in University of Manitoba as assistant professor in pathology. I have received eight awards including one CIHR resident research award. I also received The Samuel R. McLaughlin Fellowship scholarship of $13, 000. I have more than 20 publications in peer reviewed journal, 12 as a first or last author. I am a reviewer of Brain pathology journal. My area of interest includes brain tumors.

Authors

Namita Sinha 1, Sherry Krawitz 1, Jai J.S. Shankar 2, Saranya Kakumanu 3, Ken Aldape 4, Marc R.Del Bigio 1.

  1. Department of Pathology, University of Manitoba, Winnipeg, MB, Canada.
  2. Department of Radiology, University of Manitoba, Winnipeg, MB, Canada.
  3. Cancer Care Manitoba, University of Manitoba, Winnipeg, MB, Canada.
  4. Laboratory of Pathology, National Cancer Institute, NIH, Bethesda, Maryland, USA.

Target Audience:
Pathologists, Residents

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

Glioblastoma, IDH-wildtype with FGFR3-TACC3 fusion has unusual histologic, molecular and clinicoradiologic characteristics

Abstract

According to 2021 World Health Organization (WHO) classification, term ‘Glioblastoma’ is reserved for CNS WHO grade 4 astrocytic neoplasm that is IDH-wildtype. A small subset of glioblastomas may have unusual clinical, histological and molecular profiles that may need appropriate molecular work-up for definitive diagnosis, and some of them may be reported as high-grade glioma, not otherwise specified, if complete molecular work up is lacking. We present two cases: a 48-year-old female with imaging revealing right occipital solid, cystic, mass demonstrating nodular calcification; and a 53-year-old male with imaging revealing multifocal enhancing mass with extensive calcification in the right parietal, occipital and temporal regions. The cerebral tumors in both patients were relatively circumscribed high-grade glioma composed of GFAP immunoreactive monomorphic ovoid cells, with endothelial proliferation, predominantly infarct-type necrosis, and abundant calcospherites. Both tumors showed occasional mitosis with ki-67 of ~ 5-10%. Mass array analysis showed no IDH, H3F3A, BRAF V600E mutation in these two cases and revealed TERT promoter mutation in the second case. Because of unusual histology, methylation profiling was pursued in these two cases that matched to glioblastoma. Interestingly, NGS study showed FGFR3-TACC3 fusion in both the cases. Follow-up imaging showed tumor progression in these two patients, with recurrence at 9 months in the second patient. Both the patients are clinically well at 7 months and 15 months of follow-up. A few case reports are published with similar histologic and molecular findings. Our cases contribute to expanding histologic, molecular and clinical spectrum of FGFR3-TACC3 fused glioblastoma.