Unilobar congenital pulmonary lymphangiectasis mimicking congenital lobar emphysema: an underestimated presentation?

Background: Congenital lobar emphysema (CLE) is characterized by unilobar alveolar distension secondary to bronchomalacia or absent cartilage. In contrast, congenital pulmonary lymphangiectasis (CPL) is defined as distended lymphatics in the bronchovascular bundle, in the interlobular septa, and in the subpleural space. Little information is available regarding the radiologic presentation of CLE as it correlates with histological diagnosis.

Methods: In a retrospective chart review from 1995 to 2002, 8 patients (5 boys and 3 girls) with clinical and radiologic diagnosis of CLE were reviewed.

Results: The mean age at diagnosis was 26 months (range, 11 days to 10 years). All but one had classic respiratory symptoms of CLE. Six of 7 chest computed tomography (CT), scans were suggestive of CLE. Of 8 patients, 3 were treated without pulmonary resection with resolution of symptoms. Five patients underwent lobectomies, and histology results showed CPL in 3. CT failed to identify CPL in all cases.

Conclusions: Diagnosis of CLE is not as straightforward as the literature suggests. Even retrospectively, radiologic distinction between CLE and CPL could not be achieved by an experienced pediatric radiologist. CPL, thus, mimics CLE clinically and radiologically and, therefore, should be considered in the differential radiologic diagnosis of CLE.