THE VARIED MANIFESTATION OF PULMONARY-ARTERY AGENESIS IN ADULTHOOD

Objective: Unilateral pulmonary artery agenesis (UPAA), a rare congeni tal anomaly that is frequently associated with other cardiovascular ab normalities, is usually diagnosed in childhood. Most patients who have no associated cardiac anomalies have only minor Or absent symptoms an d survive into adulthood. The conditions of such patients are frequent ly misdiagnosed in adulthood. In this report, we describe six patients with UPAA in whom the diagnosis was first established in adulthood. T he varied clinical presentation of these patients is reviewed and the relative effectiveness of a variety of diagnostic tests is compared. S ubjects and methods: During the period January 1987 through December 1 990, six male patients, aged 17 to 20 years, were found to have UPAA a t the time of their medical screening for enrollment into the armed fo rces, The diagnosis was based on history, clinical and imaging examina tions, including chest radiography, ventilation-perfusion lung scan, d igital subtraction angiography (DSA), computed tomography (CT), and ma gnetic resonance imaging (MRI). Results: In four of the patients, the UPAA was on the left side and in two it was on the right A right aorti c arch was present in three patients and other cardiovascular anomalie s were found in three. Pulmonary function studies showed a mild restri ctive pattern in four. In contrast to previous reports, the ventilatio n scan showed a diminished ''wash in'' and ''equilibrium'' phase witho ut a delayed ''wash out'' phase on the affected side in all patients. Selective bronchography through the fiberoptic bronchoscope revealed i psilateral mixed-type bronchiectasis in two of four patients studied a finding of clinical significance that has not been described previous ly. In all cases, the diagnosis was made by DSA. CT of the thorax (n=6 ) and MRI (n=4) were diagnostic in all cases in which they were perfor med, but added no significant information. Conclusion: UPAA is frequen tly misdiagnosed in adulthood and is often not considered in the diffe rential diagnosis of the unilateral hyperlucent lung. Clinicians and r adiologists should be aware of the possibility of undiagnosed cases in adults, with many atypical characteristics.