Cystic pulmonary hamartoma simulating posterolateral diaphragmatic hernia.

Posterolateral diaphragmatic hernias and cystic hamartomatous malformations of the lung can cause actue respiratory distress in the immediate postnatal period. The clinical and radiological features of these two conditions can be similar. Owing to misdiagnosis, the surgical approach was inappropriate in 2 of 26 patients diagnosed as having posterolateral diaphragmatic hernias on admission. During the same period, 5 cases of congenital cystic lung disease were treated surgically. Three of these patients were admitted in severe respiratory failure within 48 hours of birth, and in 2 of these cases the wrong diagnosis was made. The clinical features of these two easily confused congenital anomalies are discussed, and the main differentiating points on the chest radiographs are presented.