Accessory diaphragm--review of 31 cases in the literature.

The authors report a case history of a male newborn at term, presenting with an accessory diaphragm in the right hemithorax, and an associated lung hypoplasia, revealed by a transient respiratory distress. The review of 31 cases published in the literature confirm the rare occurrence of this malformation. The diagnostic difficulties are discussed. The advantages of both MRI and CT scanning are compared. Pulmonary, vascular, or diaphragmatic abnormalities were due either to the isolated diagnosis or to its possible associated malformations. Operative management is often considered in view of the progressive respiratory complications. Excision of the accessory diaphragm does not necessarily solve the problem of a coexisting lung hypoplasia.