No abstract available.
Chickens* ; Embryonic Structures* ; Influenza, Human* ; Orthomyxoviridae*

Tracheal gaenesis is an extremely rare congenital anomaly and is characterized by totally or partially undeveloped trachea. In many instances, the lesion has been associated with malformations in other organ systems. This anomaly is classified into 3 types based on developmental period of the respiratory tract. We report a case of tracheal agenesis with tracheoesophageal fistula in a 2-hour-old male. Postmortem examination revealed that the upper and mid portion of the trachea was absent but 1 cm segment of the trachea above the carina was present. The proximal end to this trachea opened to the esophagus by a fistula, 1 cm in diameter. The well-formed larynx ended blindly in a fibrous sac at which thyroids and cartilage islands are noted. Associated anomalies were bilobed right lung and single umbilical artery.