Kelly-Hedrick, MargotFrerich, Jason MPeairs, Emily MCardona, Diana MArcot, RohithSmith, BrandonAbern, MichaelMiller, ChadAbd-El-Barr, Muhammad M2023-04-012023-04-012022-122042-88122042-8812https://hdl.handle.net/10161/26949Dermoid cysts rarely present in the retroperitoneal space or during adulthood. In this case report, we describe the clinical presentation, operative and post-operative course of a 31-year old with a retroperitoneal dermoid cyst. The patient presented with buttock and leg pain/paresthesia found to have a retroperitoneal mass between the psoas muscle and L5/S1 disk space. We describe the operative approach, including intra-operative images, of the resection by a team of urologists and neurosurgeons. The histology is also presented. Finally, we discuss the benefits of use of intra-operative ultrasound and neuromonitoring.Journal article2023-04-01