A case of pilocytic astrocytoma with BRAF v600e mutation and anaplastic features occurred in adult temporal lobe

Abstract

A 28-year-old woman was admitted to the hospital for headache and visual field abnormality. Magnetic resonance imaging (MRI) showed a tumor in the right temporal lobe, with heterogeneous enhancement in gadolinium-enhanced Tl-weighted imaging. Craniotomy and tumor resection were performed, and the histopathological findings showed predominantly high cellularity, which included proliferation of atypical astrocytic tumor cells, small spindle cells, and epithelioid/rhabdoid cells, accompanied by pseudopalisad-ing necrosis and microvascular proliferation. Mitotic figures were frequently observed. However, there are also several areas of low cellularity, where piloid tumor cells proliferated forming fascicular or loose reticular structures, accompanied by Rosenthal fibers and eosinophilic granular bodies. Tumor cells were negative for IDH-1, and the BRAF V600E mutation was detected. Postoperatively, the patient underwent local brain radiotherapy (60 Gy, 2 Gy/day) and chemotherapy with temozolomide and bevacizumab and did not have a recurrence within a year after surgery. Herein, we report the findings from a unique case of PA with BRAF V600E mutation and anaplastic features. We plan to perform further genetic analysis and collect follow-up information.