[The differential diagnosis of the unilateral by hyperlucent lung. Two case reports (author's transl)].

The "unilateral hyperlucent lung" is a roentgenologic diagnosis based on an increased radiolucency of one lung. Aetiology and pathogenesis of this clinical syndrome are discussed together with two own case reports about a 9-year-old girl and a 3-month old boy. Anamnesis, bronchography, scintigraphy and angiocardiography in the girl revealed a Swyer-James syndrome, where typically only one lung is damaged by obliterating bronchiolitis. In the patient the pulmonary changes developed subsequently to a measles-pneumonia, possibly enhanced by an additional pollinosis. The 3-month old infant had a left-sided pulmonary artery hypoplasia and obstructive bronchitis in both lungs. Up to its 7th month of life the child developed sufficiently under conservative therapy, but then a life threatening pneumonia with obstructive bronchitis and respiratory failure occurred, 3 weeks of artificial respiration were without success. The subsequent pneumectomy revealed a hypoplasia of the left lung and a big tracheal cyst as cause of the severe obstruction.