A 13-month-old male infant was admitted to LeBonheur Children's Medical Center, Memphis, with cough, wheezing, and cyanosis. Before admission he had been treated for three days for pneumonia, but he was referred to LeBonheur Children's Medical Center after chest roentgenograms (Fig 1, left and right) obtained elsewhere showed an apparent mass. The infant had been born by cesarean section because of abruptio placenta at 33 weeks' gestation. He required ventilatory assistance for ten days after birth and remained hospitalized until 7 weeks of age. He was well until he developed respiratory distress at 4 months of age. He subsequently had multiple hospital admissions for intermittent episodes of respiratory distress with wheezing, which were diagnosed as either bronchiolitis or pneumonia.
On physical examination he was an alert, active infant in no distress. Respirations were 48/min without retractions. Diffuse, coarse inspiratory and expiratory rhonchi and occasional expiratory wheezes were heard bilaterally. Auscultatory