Which syndrome is classified under pulmonary air-leak syndromes?

Pulmonary air-leak syndromes are characterized by conditions where air leaks into the pleural space or other compartments of the thorax, which can lead to significant respiratory issues. Pneumothorax is a condition specifically marked by the presence of air in the pleural cavity, which can collapse the lung on the affected side. This occurs when air enters the pleural space, often due to a rupture of an air-filled space in the lung, trauma, or certain medical procedures.

In contrast, pneumonia involves infection and inflammation of the lung tissue rather than air leakage. Asthma is primarily a condition marked by inflammation and narrowing of the airways, leading to wheezing and difficulty breathing, but does not involve air leaking into the pleural space. Bronchitis, which refers to the inflammation of the bronchial tubes, also does not fit into the category of pulmonary air-leak syndromes. Therefore, pneumothorax is correctly identified as a syndrome that falls under the classification of pulmonary air-leak syndromes.