Adult gastric duplication: an unknown condition within the spectrum of gastric submucosal lesions.

Background: Gastric duplication is an uncommon condition in adults representing only 4-8% of all gastrointestinal duplications. It develops as a cystic growth within the thick gastric wall that is surrounded by a layer of smooth muscle and lined with gastric mucosa. It is usually asymptomatic but may present with nonspecific abdominal symptoms as well as cyst-related complications such as gastrointestinal (GI) bleeding, ulceration and even pancreatitis. They are difficult to distinguish from other gastric submucosal lesions and may also mimic a gastrointestinal tumor (GIST) or mucinous cyst of the pancreas. Endoscopic ultrasound (EUS) is the most widely used diagnostic procedure and histology provides a definitive diagnosis.

Case Report: We report the case of a 36-year-old female patient with a history of a "contained" perforated gastric ulcer that was managed conservatively. The patient was diagnosed with a gastric GIST which prompted a laparoscopic subtotal gastrectomy and Roux-en-Y reconstruction with a good postoperative outcome.

Discussion: The definitive histological diagnosis was gastric duplication. Thus, the previous diagnosis of a "contained" perforated gastric ulcer was in fact a complication of the gastric duplication itself.