Atypical Presentation of a Retroperitoneal Schwannoma Mimicking Gastrointestinal Stromal Tumor (GIST): A Case Report

Schwannoma is a rare benign tumor that comes from the Schwann cells that sheath the peripheral nerves. We report the case of a 30 years old female patient who presented with non-specific abdominal pain and swelling in the left lumbar region for one year. CT scan findings revealed large soft tissue mass at left mid abdomen related to small bowel possibly Gastro-intestinal stromal tumor (GIST). USG findings revealed intra-abdominal cystic mass. After diagnosis patient was prepared for surgical removal. Patient was underwent complete surgical excision with an uneventful postoperative course. The histopathological study confirmed the nature of Schwannoma. Complete surgical excision remains the gold standard for the management of these tumors. The preoperative diagnosis is usually difficult due to their rare and non-specific clinical and radiological features; however, the definitive diagnosis is based upon histopathological examination and immune-histochemical.