Case Report: Molecular Diagnostics and Clinical Courses of Two Adult Spinal Pilocytic Astrocytoma Long-Term Survivors With GTF2I::BRAF Fusion

Authors

• Lorenzo Argao
• Pinar E Zerk
• Hsiang-Chih Lu
• Zied Abdullaev
• Martha Quezado
• Michelle L Cassidy
• Bennett Mclver
• Anna Choi
• Marissa Panzer
• Renee Tweneboah-Koduah
• Lily Polskin
• Marta Penas-Prado
• Paul Park
• Nathan Clarke
• Kenneth Aldape
• Jacob Mandel
• Byram H Ozer

Language

English

Publication Date

1-1-2026

Journal

Frontiers in Oncology

DOI

10.3389/fonc.2026.1670639

PMID

41858343

PMCID

PMC12995792

PubMedCentral® Posted Date

3-4-2026

PubMedCentral® Full Text Version

Post-print

Abstract

Introduction: Pilocytic astrocytomas are driven by BRAF and mitogen-activated protein kinase (MAPK) alterations, typically KIAA1549::BRAF fusions. A rare GTF2I::BRAF fusion has been described, but little is known about these cases.

Case report: Here, we report two cases with GTF2I::BRAF fusions. Case 1 is a 36-year-old man initially diagnosed with myxopapillary ependymoma at the conus medullaris with three recurrences over 23 years requiring two surgeries, three rounds of radiation therapy, and one round of lapatinib/temozolomide. A distant disease focus in T3/T4 was sampled and tested with modern diagnostic techniques revealing a pilocytic astrocytoma on histology and methylation profiling. The patient has subsequently had stable clinical and radiographic findings. Case 2 is another 36-year-old man initially diagnosed with meningitis and later neurosarcoid who underwent biopsy after 12 years when his spinal leptomeningeal disease continued to progress and an intraventricular non-enhancing nodule emerged as a separate focus. Sampling of the leptomeningeal disease led to a diagnosis of pilocytic astrocytoma by histology and a divergent methylation profile. The patient has remained neurologically stable under radiographic surveillance without any intervention.

Results: Radiographic, histological, and molecular data are presented for both cases and compared against the only other reported GTF2I::BRAF CNS case, as well as canonical versions of pilocytic astrocytoma.

Conclusion: To our knowledge, this is only the second case series highlighting a unique GTF2I::BRAF fusion and the first to describe it in adults in a spinal location. The manuscript contributes documentation of a rare fusion and tumor presentation to guide clinicians and potential research avenues.

Keywords

BRAF fusion, case report, methylation profiling, pilocytic astrocytoma, spinal tumor

Published Open-Access

yes

Recommended Citation

Argao, Lorenzo; Zerk, Pinar E; Lu, Hsiang-Chih; et al., "Case Report: Molecular Diagnostics and Clinical Courses of Two Adult Spinal Pilocytic Astrocytoma Long-Term Survivors With GTF2I::BRAF Fusion" (2026). Faculty, Staff and Students Publications. 7229.
https://digitalcommons.library.tmc.edu/baylor_docs/7229