Abnormal tracheal morphology Tracheal duplication cyst 2019-07-05T19:01:46Z Tracheal duplication cyst is a rare congenital malformation presenting in childhood with stridor or dysphagia from a mass effect on the trachea or esophagus. The features of the tracheal duplication cyst are similar to those of bronchogenic duplication cyst and laryngeal duplication cyst, but with histopathological features of the trachea. The trachea is known to originate from the respiratory diverticulum, a ventral outpouching of foregut lumen. The postulated embryological basis of a tracheal duplication cyst may be similar to that of the anomalous bronchi and is a result of abnormal budding of the bronchial tree during the fourth to sixth weeks of embryogenesis. A cyst in the trachea, whose wall is made up by tissue similar to the bronchial tree, including cartilage and smooth muscle, and is lined by secretory respiratory epithelium composed of cuboid or columnar ciliated epithelium.