The chest radiograph of patients with UAPA typically shows asymmetric lung fields, with an ipsilateral small hemithorax holding a
hyperlucent lung.
Chest radiographic signs include a unilateral
hyperlucent lung field with collapse of the lung, tracheal deviation and mediastinal displacement (see Figure 4) (Ho & Gutierrez 2009).
The differential diagnosis on chest radiograph includes unilateral agenesis or extrinsic pulmonary artery occlusion from tumor, pulmonary embolism, bronchial obstruction (central or extrinsic) causing compensatory emphysema, bronchial atresia, pseudo hyperlucent lung in patients after mastectomy, absence or atrophy of pectoral muscles, and shoulder girdle.
On the contrary, in unilateral agenesis of the pulmonary artery, the hilar shadow is absent and there is contralateral hyperlucent lung.
Swyer-James Macleod syndrome is a rare acquired cause of unilateral hyperlucent lung.
Because of the decreased parenchymal perfusion, this syndrome is often mentioned as translucent or
hyperlucent lung (5,6).
Utility of ventilation and perfusion scan in the diagnosis of young military recruits with an incidental finding of hyperlucent lung.
Scintigraphy, angigraphy and computed tomography in unilateral hyperlucent lung due to obliterative bronchiolitis.
In 1953, Swyer and James (1) described unilateral,
hyperlucent lung syndrome in a 6-year-old boy.
5) Patients can be completely asymptomatic with
hyperlucent lung field being an incidental finding on the chest radiograph taken for other indications.
Chest radiograph showed
hyperlucent lungs with atelectatic bands in both lower zones and blunting of the right costophrenic angle.
