Two Cases of Duplication of the Alimentary Tract Lined with Ciliated Columnar Epithelium

We report two cases of duplication of the alimentary tract lined with ciliated pseudostratified columnar epithelium. One patient is an asymptomatic 14-year-old male. Duplication of the stomach was incidentally found by computed tomography. On laparotomy, the duplication cyst, 7×4×4 cm in size, was found to be firmly attached to the posterior wall of the stomach, and in part shared a common muscular wall with the stomach. Histologically, the cyst was lined with ciliated pseudostratified columnar epithelium, and it's wall was composed of three welldeveloped muscular layers. The other patient is a 15-year-old male with complaints of abdominal pain and vomiting. Laparotomy was carried out because of ileus. A duplication cyst, 10×6.5×6.5 cm in size, was found on the ileum and was complicated by volvulus. Histologically, the cyst was lined with ciliated pseudostratified columnar epithelium, and there was a common muscular layer between the cyst and the ileum. Duplications of the alimentary tract are of various types, presumably because they arise from several types of developmental errors. As is often the case with duplication of the esophagus, in our cases the cysts were lined with ciliated columnar epithelium. Thus, based on anatomical and histopathological features, we favor a primitive foregut origin for our cases.