Long-standing retroperitoneal schwannoma in a 36-year-old female: A case report.

Introduction: Schwannomas are encapsulated nerve sheath tumors derived from Schwann cells, primarily found in the head, neck, and extremities. Retroperitoneal schwannomas are rare and typically asymptomatic.

Case Presentation: A 36-year-old female presented with a long-standing, asymptomatic right lower abdominal mass. Imaging revealed a retroperitoneal cystic mass displacing adjacent structures. The tumor was surgically excised, and histopathology confirmed the diagnosis of schwannoma. The patient had an uneventful postoperative recovery and remains symptom-free with no signs of recurrence.

Discussion: Schwannomas are benign nerve tumors primarily affecting women aged 30 to 50. This case involved an asymptomatic retroperitoneal schwannoma displacing the inferior vena cava without neurological symptoms. Imaging methods like ultrasound and CT are useful but often lack definitive results, and preoperative biopsy is not recommended due to risks of vascular injury. While conservative management may be suitable for asymptomatic cases, complete surgical excision is crucial to prevent recurrence. Although some suggest partial excision, most literature supports curative resection with negative margins, as incomplete removal can lead to a 10-20 % recurrence rate. The patient underwent successful complete resection.

Conclusion: Retroperitoneal schwannomas are rare tumors that are difficult to diagnose preoperatively. Radiologic findings are usually nondiagnostic. The treatment of choice is complete surgical excision.