Submitted by Gabe Sexton, MD and Thomas Pearce, MD, PhD
Case Presentation
A young female in her 2nd decade presented with new onset, episodic inability to understand written or spoken words. Her symptoms also included some difficulty with speech.
Radiologic Findings
Magnetic resonance imaging (MRI) of the brain identified a T2 FLAIR hyperintense lesion within the left posterior temporal subcortical white matter.
Histologic Findings
Excision and biopsy of the left temporal lesion demonstrated a biphasic neoplasm with glial and neuronal elements forming pseudopapillary arrangements (Figure A) as well as rare rosette-like structures with central neuropil (Figure B). Scattered cells contained granular, intensely eosinophilic intracytoplasmic material and a myxoid background was evident in some areas. Mitotic activity was not appreciably increased and necrosis was absent. A definitive interface between tumor and uninvolved brain was not seen. GFAP (Figure C) and Olig2 stains highlighted glial cells in pseudopapillary structures. Synaptophysin staining was positive in the neuronal component (Figure D), primarily located between pseudopapillary structures, and in neuropil within the rare rosette-like structures. The Ki-67 proliferation index was approximately 3%-5%. Next-generation sequencing (GlioSeq) identified SLC44A1::PRKCA gene fusion.
