Horseshoe lung with left lung hypoplasia.

Horseshoe lung is an uncommon congenital malformation in which the bases of the right and the left lungs are fused to each other by a narrow isthmus posterior to the cardiac apex. So far 22 cases have been described: most of these were associated with right lung hypoplasia and the scimitar syndrome. A horseshoe lung anomaly with left lung hypoplasia is described.