Main-stem bronchial atresia: Intrauterine sonographic diagnosis

Bronchial atresia probably results from a vascular insult either after the 15th menstrual week when the bronchial branching is complete or between the fifth and 15th menstrual weeks with distal branching dissociated from the atretic segment. We wish to present a patient with atresia of the right main-stem bronchus and tracheal stenosis whose serial intrauterine sonography documented an enlarged echogenic right lung with both mediastinal shift and anechoic, mucus-filled, dilated bronchi noted at 24.4 weeks after normal scans at 15.6 and 20.3 weeks. The right lung became relatively smaller during further intrauterine development while the anechoic bronchi became larger. The sonographic findings suggest that atresia occurred after the bronchial branching was completed.