Adenocarcinoma Arising in Gastric Duplication Cyst

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Alimentary tract duplications may occur from the oral cavity to the rectum. The ileocecal valve area is the most commonly affected site. 1 Gastric duplication cysts are relatively rare congenital anomalies that constitute only 2% to 8% of alimentary tract duplications. 2 These gastric duplication cysts are mostly discovered in children, with most patients presenting during the first year of their life. Associated symptoms often include nausea, vomiting, hematemesis, and abdominal pain. 3 Ulcer-ation, bleeding, rupture, and fistula formation are known complications. There have been a few case reports on gastric duplication cysts associated with malignancy. Previously reported malignant lesions have included adenocarcinoma, mixed ad-enocarcinoma and squamous cell carcinoma, and neuroendo-crine carcinoma. Here, we report a case of adenocarcinoma arising in a gastric duplication cyst, the first such occurrence to be reported in Korean patients. A 56-year-old man was admitted to Asan Medical Center with a gastric submucosal lesion that was detected by esopha-gogastroduodenoscopy during a regular checkup (Fig. 1A). The overlying gastric mucosa was normal except for a slight elevation , and no associated symptoms were present. His medical and family histories were unremarkable. A complete blood count and serum chemistry tests were normal. A computerized tomography (CT) scan revealed a 5.5-cm low attenuating cystic mass located in the submucosal layer along the greater curvature of the body (Fig. 1B). The radiologic differential diagnoses were cystic degeneration of the neurogenic tumor, gastrointesti-nal stromal tumor (GIST), and gastric duplication cyst. The patient underwent a wedge resection to remove the lesion, and an unilocular cystic mass measuring 5.5×3.5×2.5 cm was identified in the proper muscle layer with smooth and intact overly-ing gastric mucosa. Thick, yellowish fluid filled the cyst and there were no connections between the cyst and the lumen of the stomach. The cystic wall had a regionally thickened portion (0.6 cm) and its cut surface was firm and granular (Fig. 1C). Microscopically, the cystic wall was comprised of all of the layers of the stomach wall (from the mucosa to the muscularis pro-pria). The proper muscle layer of the cyst merged into the proper muscle layer of the stomach, sharing a common wall (Fig. 1D). The lining epithelial cells of the cyst …