Abstract
BACKGROUND: The authors report on a patient who presented with an extremely large presacral schwannoma and subsequent mass effect-induced hydronephrosis and kidney failure. To the authors' knowledge, this case represents the largest radiographically verified spinal schwannoma in the medical literature. The tumor presented here was more than three times as large as a typical giant schwannoma. While smaller presacral schwannomas are usually uncomplicated surgical cases, the supergiant schwannomas described here create significant surgical challenges. OBSERVATIONS: The extremely large size of this nerve sheath tumor introduced a level of surgical complexity not seen in most spinal schwannoma cases. The authors hope that this case informs surgeons regarding the approach to excision of giant spinal schwannomas. LESSONS: The resection of giant spinal schwannomas is likely to involve one or more lengthy surgeries, and the resection volume can be limited by excessive bleeding. Physicians approaching these large, benign spinal tumors should be aware of the challenges of surgery duration and hemostasis before approaching a tumor of this kind. https://thejns.org/doi/10.3171/CASE24224.