Case Report: Rare duodenal schwannoma diagnosis and treatment process report.

Background: Duodenal schwannoma is a rare benign mesenchymal tumor originating from the Schwann cells of peripheral nerves. Its accurate diagnosis remains challenging owing to non-specific clinical and radiological features. Case presentation: This report describes the clinical diagnosis and treatment of a duodenal schwannoma in a 30-year-old female patient. An initial outpatient gastroscopy revealed a submucosal lesion in the duodenum, with differential diagnoses including ectopic pancreas or gastrointestinal stromal tumor. Furthermore, plain and contrast-enhanced abdominal CT scans showed a nodule protruding into the duodenal bulb, suggesting a benign lesion. The patient underwent endoscopic submucosal dissection to remove the tumor. During the procedure, a 1.0 × 1.6 cm submucosal nodule was identified on the anterior wall of the duodenal bulb, with a mildly eroded and slightly depressed surface. The lesion was firm and non-mobile. Histopathological examination of the resected specimen confirmed a spindle cell tumor originating from the duodenal mucosa, leading to a definitive diagnosis of duodenal schwannoma. Conclusion: Duodenal schwannoma is a rare submucosal tumor traditionally treated with surgical resection. This case highlights the safety and efficacy of endoscopic submucosal dissection in the treatment of duodenal schwannomas, allowing complete tumor resection while preserving gastrointestinal function. In addition, early detection and complete resection are key for preventing recurrence and potential complications.