Three Years of Progression-free after Biopsy of BRAF V600E-negative Ganglioglioma in the Adult Brainstem: A Case Report and the Literature Review

Ganglioglioma, a glioneuronal neoplasm, typically presents in adolescents' temporal lobes. While pediatric brainstem gangliogliomas (BSGGs) are well documented, adult BSGGs are limited, resulting in a lack of comprehensive understanding of their pathophysiology and prognosis. A 41-year-old woman who presented with dizziness and numbness in her right upper extremity and right face underwent radiological examination. A dorsally exophytic tumor in the medulla oblongata was identified. Moderate uptake of ¹¹C-methionine on positron emission tomography suggests a low-grade glioma. Histopathological evaluation, following a suboccipital craniotomy and biopsy under neuromonitoring, confirmed the tumor as a mix of neoplastic ganglion cells and glial cells, which exhibited immunoreactivity for chromogranin A and OLIG2, respectively. Eosinophilic granular bodies and Rosenthal fibers were also observed. These findings confirmed the diagnosis of a ganglioglioma. The BRAF V600E mutation tested negative by real-time polymerase chain reaction. No postoperative adjuvant treatment was administered, and no progression of the residual tumor was noted 34 months post-surgery. Increased reporting of adult BSGGs, complete with detailed radiological, molecular, and genetic profiles, as well as their clinical course, is essential for clarifying our understanding of this rare entity's oncogenic pathway, optimal management strategy, and prognosis.