Unilateral hyperlucency of a lung is seen in the Swyer-James-MacLeod Syndrome (SJMS).
Features of SJMS:
(1) The patient experiences bronchiolitis obliterans during infancy or childhood.
(2) There is subsequent occurrence of severe and/or recurrent pulmonary infections.
(3) This results in bronchiectasis and severe emphysema affecting a pulmonary segment, lobe or entire lung
(4) The pulmonary artery to the affected lung becomes hypoplasia secondary to fibrosis of interalveolar septae.
(5) The changes cannot be explained by bronchial obstruction or congenital hypoplasia of the lung.
The emphysema results in hyperlucency of the affected lung on chest X-ray.
The affected lung may develop a bacterial abscess or fungal infection.
