Gastric schwannoma with high accumulation on fluorodeoxyglucose-positron emission tomography resected by non-exposed endoscopic wall-inversion surgery.

Gastric schwannoma is a relatively rare tumor arising from Auerbach plexus in the muscle layer of the gastric wall, and constitutes 0.1% to 0.2% of all gastric tumors and 5% of benign non-epithelium-related gastric tumors. We report the case of a 49-year-old woman in whom upper gastrointestinal endoscopy revealed an approximately 2-cm submucosal tumor on the anterior wall of the fornix of the stomach. Contrast-enhanced computed tomography revealed a homogeneously enhanced lesion (~ 17 mm) in the upper third of the stomach as well as a lesion (~ 25 mm) on the left kidney that was strongly enhanced in the early phase. An 18F-fluorodeoxyglucose positron emission tomography scan revealed high accumulation that is characteristic of gastric tumors. The possibility of malignancy was not completely excluded, and the gastric tumor was resected by non-exposed endoscopic wall-inversion surgery. The patient was discharged with a good prognosis 5 days after surgery. In conclusion, non-exposed endoscopic wall-inversion surgery is a minimally invasive and effective method for resecting small gastric submucosal tumors (diameters < 3 cm) for which preoperative diagnosis is difficult.