Case In Point: Unilateral agenesis of the diaphragm

October 1, 2006

Unilateral agenesis of the hemidiaphragm is a very rare congenital anomaly. We present the case of an adult who was evaluated for persistent cough. Unilateral agenesis of the diaphragm was an unexpected finding on a chest radiograph.

The case

A 42-year-old man presented with nonproductive cough that had persisted for 2 months. His cough was preceded by nasal congestion and postnasal drip. He was initially treated with a course of antibiotics by his primary care physician, with no improvement in symptoms. He denied dyspnea, fever, chills, night sweats, and chest pain.

The patient had no history of pulmonary disease, chest wall trauma, or motor vehicle accidents, and he had no history of any respira-tory difficulties in childhood. At the time of evaluation, he was taking an oral antihistamine and us-ing a nasal saline spray. He worked as a machine operator and denied any use of tobacco, alcohol, or recreational drugs.

On examination, the patient was comfortable at rest. His vital signs were stable, and he was afebrile. Mild nasal congestion was noted bilaterally. He had no clubbing or lymphadenopathy.

Chest examination revealed good air entry bilaterally with no wheezing or crackles. The percussion note was markedly dull over the left mid-chest. Sounds akin to bowel sounds were auscultated in the left lower chest posteriorly. Bronchi- al breath sounds were not audible. The cardiovascular examination was unremarkable, and an abdominal examination did not reveal any masses.

Results of routine blood tests were within normal limits. A chest radiograph was obtained (Figure 1). The chest radiographic findings prompted a CT scan of his chest (Figure 2).

The radiologic features were consistent with agenesis of the left hemidiaphragm and intrathoracic left kidney and bowel loops. Previous chest imaging was not available for comparison.

The clinical impression was that his cough was secondary to postnasal drip syndrome and that the chest imaging findings were incidental. He was informed of his chest radiographic findings.

The patient's cough completely resolved with a course of intranasal corticosteroids.

Discussion

In utero failure of the pleuroperitoneal membrane to fuse with the septum transversum leads to the development of a congenital diaphragmatic hernia. The diagnosis is usually made at birth when the infant has severe respiratory complications resulting from pulmonary hypoplasia.

At the most extreme end of the spectrum of congenital diaphragmatic hernias is agenesis of the hemidiaphragm, which results from nondevelopment of the embryologic origins of the diaphragm and is usually left-sided.

Agenesis of the hemidiaphragm is exceedingly rare in adults. To our knowledge, there have been only 6 previous case reports of this condition in adults in the English literature. Only 2 were confirmed to have no diaphragmatic remnants--thus, true agenesis.1,2 In other cases, there were remnants3 or the diagnosis was made radiographically.4,5

Management of agenesis of the hemidiaphragm in adults has been controversial. The authors of 2 case reports did not recommend surgical correction in asymptomatic patients, because the large pleuroperitoneal communication makes strangulation unlikely.4,5 More recently, a patient with intestinal strangulation despite a sizable defect has been reported.1

For the patient described here, conservative management was recommended, and he has remained asymptomatic.

References:

REFERENCES


1. Sheehan JJ, Kearns SR, McNamara DA, et al. Adult presentation of agenesis of the hemidiaphragm.

Chest.

2000;117:901-902.
2. Anderson CD, Eliason J, Roberts JR, Sharp KW. Bilateral diaphragmatic agenesis in an adult complicated by a paraduodenal hernia.

Am Surg.

2003;69:523-525.
3. Singh G, Bose SM. Agenesis of hemidiaphragm in adults.

Aust N Z J Surg.

1993;63: 327-328.
4. Travaline JM, Cordova F. Agenesis of the diaphragm.

Am J Med.

1996;100:585.
5. Tzelepis GE, Ettensohn DB, Shapiro B, McCool FD. Unilateral absence of the diaphragm in an asymptomatic adult.

Chest.

1988;94: 1301-1303.