Background <p>Gangliogliomas are rare tumors primarily arising from the central nervous system, mostly in the temporal lobes, with brain stem involvement being particularly infrequent. To the best of our knowledge, this is the first reported instance of a brainstem ganglioglioma exhibiting an extension to foramen of Luschka.</p> Case presentation <p>We present a unique case of ganglioglioma of the brainstem. 23-year-old Turkish patient presented with flashing lights in the peripheral visual fields. Imaging studies revealed a distinct mass lesion adjacent to the brainstem, demonstrating an unusual exophytic growth pattern that extended towards the foramen of Luschka. Surgical intervention was performed to prevent tumor progression and obtain a definitive diagnosis. The surgical approach employed was the telovelar approach, which provides excellent visualization of the posterior fossa. Histopathological examination of the resected specimen confirmed the diagnosis of grade 1 ganglioglioma. Postoperative magnetic resonance imaging scans displayed gross total resection of the tumor. The patient’s postoperative course was uneventful, and the initial symptom of flashing lights resolved in the postoperative period.</p> Conclusion <p>This case report highlights the uniqueness of a dorsally exophytic brain stem ganglioglioma extending to the foramen of Luschka. Utilization of the telovelar approach and sodium fluorescein in the surgical management of this challenging case underscores its efficacy in managing deep-seated lesions within the posterior fossa. Although presenting infrequently, gangliogliomas should be considered in the differential diagnosis of lesions of the foramen of Luschka because early recognition is important for the management and prognosis.</p>