Cranio-Orbital Pretemporal Approach for Microsurgical Resection of Hypothalamic Rosette Forming Glioneuronal Tumor with Reversal of Preoperative Blindness: 2-Dimensional Operative Video.

The hypothalamic region is susceptible to involvement of several processes.1 Lesions in this region remain challenging for surgical access and treatment. Strategies include both endoscopic and microsurgical approaches.2 A cranio-orbital approach with extradural clinoidectomy and optic canal unroofing provides the necessary corridor to visualize and decompress the optic nerve/chiasm and remains an important tool in achieving complete tumor resection with favorable functional and visual outcomes.3-12 Endoscope assistance in transcranial surgery is well established, used to provide direct visualization of hidden adjacent tissues.13 A 25-year-old woman presented with headache and progressive visual loss to blindness (hand waving and light perception) on admission. Magnetic resonance imaging demonstrated a 28-mm-diameter tumor in the hypothalamic region with no significant postcontrast enhancement. She underwent right cranio-orbital craniotomy, extradural anterior clinoidectomy, and optic canal unroofing with a 2-mm high-speed diamond drill and copious irrigation. After ipsilateral falciform ligament release, the tumor capsule was coagulated, sharply opened, and resected in a piecemeal fashion. Endoscopic assistance warranted the removal of hidden parts and confirmed tumor removal. Histopathology and next-generation sequencing confirmed the diagnosis of rosette-forming glioneural tumor. Follow-up revealed gross total tumor removal on magnetic resonance imaging and complete recovery of visual function as per ophthalmologist examination. Rosette-forming glioneural tumors are considered rare and classified as World Health Organization grade I tumors usually found in the fourth ventricle.14 To our knowledge, we present the first operative video (Video 1) demonstrating the removal of rosette-forming glioneural tumor in the hypothalamic region with endoscopic assistance.