Pars sternalis diaphragmatic hernia with omphalocele: a report of two cases.

A rare type of congenital diaphragmatic hernia occurs in which there is a large opening in the anterior diaphragm between the pericardial and peritoneal cavities without a sac. This hernia is invariably associated with defects in the anterior abdominal wall and with sternal defects. More commonly, it is associated with cardiac anomalies as in the Pentalogy of Cantrell. The etiology of this hernia is undoubtedly different from the more common hernia of Morgangni, which has a sac and few associated anomalies. The etiology may be failure of fusion of the pars sternis area of the septum transversum. Only five other cases have been described.