Gastric adenomyoma mimicking gastric duplication cyst in a 5-year-old girl

Gastric adenomyoma in children is a rare benign tumor composed of a mixture of duct-like epithelial structures with smooth muscle bundles. It has been considered as a subtype of ectopic pancreas because the epithelial component resembles that in pancreatic ducts. However, it is now recognized as an independent pathologic lesion. Gastric adenomyoma is usually asymptomatic but could cause obstruction, inflammation, ulceration, and malignant transformation. Hence, to achieve diagnostic certainty and to control symptoms, complete operative resection is recommended. To the best of our knowledge, this is the first case of gastric adenomyoma mimicking a gastric duplication cyst in children.