A case of foregut gastric duplication cyst with pseudostratified columnar ciliated epithelium.

Gastrointestinal duplication is a congenital rare disease. Duplication cyst of the stomach with pseudostratified columnar ciliated epithelium is extremely rare. A 44-year-old Japanese woman visited University of Yamanashi Hospital for evaluation of an abnormal tumor detected by abdominal ultrasonography at an annual general health examination. Abdominal computed tomography indicated a subserosal cystic lesion 6 cm in diameter on the posterior wall of the stomach. The cystic lesion was resected through partial resection of the stomach. Histopathology showed that the cyst did not communicate with the gastric lumen, was covered with gastric epithelium and pseudostratified columnar ciliated epithelium with circular muscle layers, and did not contain cartilaginous tissue. Consequently, the patient was diagnosed as having foregut duplication cyst of the stomach. Gastrointestinal duplication can occur in any region of the gastrointestinal tract, but foregut duplication cyst of the stomach is rare. The present case was a subserosal cyst on the greater curvature that did not communicate with the gastric lumen and was covered with gastric epithelium and pseudostratified columnar ciliated epithelium, suggesting a foregut cyst caused by an aberrant respiratory organ.