Retroperitoneal Schwannoma Complications In A 36-Year-Old Male
Schwannomas are benign, encapsulated tumors typically arising from the Schwann cells of peripheral nerve sheaths and rarely undergo malignant transformation. Majority of schwannomas are asymptomatic, slow growing mass and present in the middle decades of life involving the head, neck or extremities. In rare cases, 1-3% of schwannomas are found in the retroperitoneal space. Typically the tumor is well demarcated without invasion, but may present with significant local adherence.
This is a case of a 36-year-old male who was incidentally found to have a 12.0x10.0x8.3cm retroperitoneal mass in the left pelvis on CT scan during an admission for acute appendicitis. CT-guided biopsy of the mass revealed a benign S100-positive schwannoma. He subsequently underwent exploratory laparotomy for excision of the retroperitoneal schwannoma. Intraoperatively, the mass was found to be tightly adhered to surrounding tissues and vessels posteriorly. Extraction resulted in significant pelvic bleed requiring additional re-explorations and control of postoperative bleeding. Histopathological examination revealed an encapsulated schwannoma with focal features of cystic degeneration. Patient has since been doing well in subsequent follow ups postoperatively.
Retroperitoneal schwannoma are typically asymptomatic, but may present with vague abdominal pain, distention, or other compressive symptoms. Surgical resection is the primary treatment of choice regardless of presence of symptoms given a lack of response to chemoradiation and risk of hemorrhage, growth, and possible malignant transformation. Due to the anatomical positioning and possibility of adherence to neighboring structures, retroperitoneal schwannoma may pose a challenging dissection. Care must be taken to avoid injury to nearby vessels and organs.