1587. Giant Presacral Schwannoma Presenting with Ureteral Obstruction and Acute Kidney Injury: Case Report and Literature Review

Authors: Sean Michael Barber, MD; Jared Fridley; Sanjay Konakondla; Jonathan Nakhla; Albert Telfeian; Adetokunbo Oyelese; Ziya Gokaslan (Providence, RI)

Introduction: Giant presacral schwannomas are rare, slow-growing tumors that are often discovered incidentally, but may also present with local pain, radicular symptoms or non-specific symptoms related to compression of pelvic or abdominal viscera. Methods: We report the case of a patient with a giant presacral schwannoma discovered on workup for acute kidney injury. Results: A 50-year-old female presented to an outside institution with malaise and was found on laboratory studies to be in postrenal acute kidney injury. Bilateral nephrostomy tubes were urgently placed, and pelvic imaging revealed a giant presacral mass (16 x 13cm) with right S1-2 sacral involvement compressing the ureters bilaterally. Ureteral stents were placed and the patient underwent gross total resection via a two-stage procedure. She first underwent L4-pelvis fixation, S1-4 laminectomies, sectioning of the right S2 nerve root and removal of the posterior part of the tumor. The following day, laparotomy was performed for removal of the ventral portion of the tumor. Total blood loss was more than 8 liters, the majority of which occurred during the anterior stage, and the patient required numerous blood product transfusions. A small portion of tumor adherent to the right internal iliac vein was left in situ. She remained neurologically stable after the procedure, and 14-month followup imaging revealed no recurrence. Conclusion: We report the rare case of a giant presacral schwannoma presenting with acute kidney injury due to ureteral obstruction. These tumors are often quite large at the time of presentation, and are often adherent to retroperitoneal and pelvic vasculature. Resection requires the cooperation of an experienced multidisciplinary team, but after gross total resection, the overall prognosis is favorable.