Association between pneumomediastinum and renal anomalies.

Bilateral renal agenesis is probably always associated with hypoplastic lungs and the characteristic facial appearance described by Potter in 1946. Pulmonary hypoplasia is also frequent in infants with polycystic disease of the kidneys (Landing, 1957), in some ofwhom the typical Potter facies may be lacking (Bain and Scott, 1960). Newborn infants with these combinations of lesions are either stillborn or die from respiratory insufficiency soon after birth. Some show evidence of extravasation of air outside the pulmonary alveoli into the interstitial tissue, and, in severe cases, this may extend into the mediastinum and pleural sacs. If the typical facial features are lacking, the infant may present with acute respiratory distress due to pneumomediastinum, and the unsuspected underlying lung and kidney lesions may be discovered only at necropsy.