Chronic unilateral hyperlucent lung. A consecutive series of 40 patients.

A clinical series of 40 consecutive patients with chronic unilateral hyperlucent lung was analysed. Swyer-James (MacLeod) syndrome turned out to be the most common diagnosis (18 patients, 45%). Other causes were localized emphysema (8 patients, 20%), congenital hypoplastic pulmonary artery (4 patients, 10%), previous massive pulmonary embolism (4 patients, 10%), bronchial carcinoma (3 patients, 7.5%), sequelae of radiation therapy (2 patients, 5%) and benign intrabronchial neoplasm (1 patient, 2.5%). The reduction of pulmonary vasculature was scored (0-9). The most extensive reduction was found in patients with Swyer-James syndrome (mean 5.8), whereas patients with bronchial cancer had the smallest changes (mean 3.0).