Unilateral pulmonary agenesis: an unusual cause of respiratory distress in the newborn.

Unilateral pulmonary agenesis is a rare disorder and is an unusual cause of respiratory distress in the newborn. It is often associated with other congenital abnormalities, as documented in about 200 cases of unilateral pulmonary agenesis in the current literature. The onset and mode of presentation are highly variable, from asymptomatic cases discovered incidentally to symptomatic cases diagnosed in early infancy. We report a newborn infant with right pulmonary agenesis associated with facial and skeletal abnormalities who presented with respiratory distress. Unilateral pulmonary agenesis should be considered in the differential diagnosis of respiratory distress in the newborn, particularly when there are other associated congenital abnormalities.