Foramen of Bochdalek

A 95-year-old woman was brought to the emergency department with hemoptysis. Erect posterior-anterior (A) and lateral (B) chest films showed a density at the base of the right lung posteriorly. A CT scan (C) revealed that the mass was the right kidney above the diaphragm and adjacent to the heart. The kidney had migrated through a foramen of Bochdalek.

Drs Robert P. Blereau, MD and Timothy J. Haley of Morgan City, La, write that a foramen of Bochdalek is a congenital posterolateral diaphragmatic hernia, which may be catastrophic in newborns. A defect in the developing pleuroperitoneal fold allows abdominal and retroperitoneal viscera to enter the chest cavity; this may compromise lung development in the fetus. The vast majority of cases of foramen of Bochdalek present at birth with acute respiratory distress; it is unusual to discover this condition as an incidental finding in an adult.

Because the right diaphragm is protected by the liver, the vast majority (88%) of these hernias occur on the left side; only 1% to 2% are bilateral. The risk of occurrence is 1 in 2200 live births; male children are predominantly affected.

Respiratory distress may develop in newborns with foramen of Bochdalek during delivery or shortly after birth. Therefore, when this defect is diagnosed in utero by antenatal ultrasonography, arrange for the delivery to occur in a tertiary care center with neonatal intensive care and pediatric surgery units. The differential diagnosis of congenital diaphragmatic abnormalities that present in neonates includes Morgagni hernia, which occurs through a space of Larrey at the anterior parasternal area, and eventration of the diaphragm.

In adults, the hernia typically presents as a posterolateral chest mass above the left diaphragm-the opposite of the presentation in this case. CT will reveal the identity of the herniated mass, which usually is retroperitoneal fat, omentum, spleen, or kidney.

This patient's hemoptysis resulted from bronchitis, which was successfully treated with antibiotics. No treatment was needed for the foramen of Bochdalek hernia with the kidney in the right side of the chest.