Unilateral pulmonary agenesis. A report of 4 cases.

Unilateral pulmonary agenesis is rare and in most of the less than 200 examples recorded there were additional congenital anomalies. Four previously unreported cases are outlined, the sequence of investigation judged safest is described, and the need to make a definitive diagnosis is emphasised--so that early in the patient's life a precise label can be attached to the radiographic abnormality to avoid repeated investigations and irrelevant and potentially dangerous treatment.