CLINICAL HISTORY.—This child was admitted to Childrens Hospital at 3 months of age. She had been well since birth, but on a routine examination the day prior to admission, the referring physician noted marked decrease in the breath sounds in the right chest.
She was the product of an uncomplicated term pregnancy and normal spontaneous delivery. Birth weight was 3,771 gm (8 lb 5 oz). There had been no illness; growth was normal, and the day prior to admission, she weighed 5,528 gm (12 lb 3 oz). The family history is of interest in the fact the mother was born with "agenesis of the middle lobe of the right lung."
The patient was a well-developed, well-nourished, 3-month-old girl in no distress. The significant physical findings were limited to the chest. No deformity was noted and there seemed to be equal bilateral excursion. The lungs were resonant to percussion but there