The incomplete interlobar fissure sign seen on the upright chest radiograph consists of a perihilar radiolucent area bordered laterally by a concave and blurred border at its periphery.

Lung-tracheal-bronchial malformations are divided according to the developmental morphology of congenital malformations. Respiratory malformations include: lung malformations, tracheobronchial malformations, malformations of the pulmonary vascular and lymphatic systems, and benign tumors of the lungs and bronchi.