LAUSR

Background Sacral schwannomas are rare tumors arising from nerve sheath Schwann cells. They are classified into 3 types: first type schwannoma arising from the sacrum, second type schwannoma eroding the sacrum, and third type schwannoma extending extensively, involving anterior, posterior, and retroperitoneal space. Among these type 2 sacral tumors, according to Klimo's classification, an eroding sacrum extending all over posteriorly, anteriorly, and laterally is still rarer. Only 38 cases have been reported in literature reviews. Only 6 cases of giant tumors of >10 cm in any 1 dimension have been reported. Case Description We present such a giant sacral schwannoma, with invasiveness eroding the sacrum; compressing the ureters, aortic bifurcation, bladder, and bowel; and presenting as lower abdominal pain, hydronephrosis, dysuria, and constipation. This is the first case reported in the literature that has described a large retroperitoneal tumor compressing retroperitoneal structures—aortic bifurcation vascular compression and ureter compression causing hydronephrosis. Conclusions Though complete resection, which caused various severe postoperative complications in the reported cases, is the best option, a less morbid procedure would be appropriate; hence we underwent subtotal excision of the tumor, with complete recovery of our patient's symptoms without neurologic deficit.