We have written a "letter to Editor" about a case of gastric dilatation caused by a symptomatic gastric duplication cyst with ectopic pancreas ingrowth, in a 13 years old boy. The Endoscopy Ultra Sound characterized the lesion and permitted the aspiration of the internal liquid. The patient underwent to laparoscopic excision of the mass and the histology revealed a gastric duplication cyst with ectopic pancreas ingrowth.