Subtotal resection of gastric duplication cysts using endoscopic submucosal dissection: A case report

Gastric duplication cysts (GDCs) are rare congenital anomalies, and consensus guidelines for their diagnosis and management are currently lacking. We report a rare case of a GDC in a female child presenting as a submucosal tumor in the gastric antrum. Subtotal resection was achieved using endoscopic submucosal dissection (ESD), resulting in complete symptom relief and pathological confirmation. This case demonstrates the therapeutic potential of ESD for intraluminal GDCs and underscores the importance of complete resection for definitive diagnosis.

A 12-year-old girl presented with abdominal distension and pain for > 1 year. Gastroscopy revealed a protruding lesion approximately 30 mm in diameter in the gastric antrum. Superficial biopsies revealed moderate chronic inflammation and intestinal metaplasia. Contrast-enhanced computed tomography showed a mass protruding into the gastric lumen with homogeneous cyst wall enhancement. Endoscopic ultrasonography identified a hypoechoic mass originating from the muscularis mucosa. The patient underwent ESD for diagnosis and symptom relief. Intraoperatively, due to firm adhesion between the cyst base and the muscularis propria, selective preservation of the adherent cyst base was performed to mitigate perforation and stenosis risks. Histopathology confirmed a GDC, with cyst lumen lined by gastric-type columnar epithelium and an outer smooth muscle layer. Focal ectopic pancreatic tissues were identified. The patient recovered without complications and remained asymptomatic during 6-month follow-up. Repeat gastroscopy showed the residual cyst wall conforming to antral mucosa, with no recurrence.

Subtotal resection of GDCs using ESD demonstrates a favorable prognosis.