Surgical and anatomical nuances in trigeminal neuralgia due to cerebellopontine angle lipoma: illustrative case.

BACKGROUND: Trigeminal neuralgia (TN) is a highly debilitating condition often caused by neurovascular compression. Less commonly, cerebellopontine angle (CPA) tumors can be the culprit, while intracranial lipomas are an exceedingly rare etiology. Treatment options include medical management and surgical interventions ranging from neurovascular decompression alone to mechanical rhizotomy and tumor resection. OBSERVATIONS: The authors present the case of a 30-year-old woman with medically refractory TN found to have a CPA lipoma abutting the root entry zone of the trigeminal nerve. A decision was made to proceed with microvascular decompression and microneurosurgical tumor partial resection. Intraoperatively, careful arachnoid dissection was performed and the tumor was debulked around the CN V transition and root entry zone. Furthermore, small venous tributaries to the superior petrosal vein were noted to be compressing the nerve and these were divided. Lastly, microneurosurgical internal neurolysis was performed. Postoperatively, the patient had complete resolution of her TN without cranial neuropathies or other complications. LESSONS: CPA lipoma is a rare etiology of TN, and surgical debulking along with vascular decompression and microneurosurgical internal neurolysis should be considered in medically refractory cases with evidence of nerve compression. https://thejns.org/doi/10.3171/CASE26382.