What is the diagnosis for pneumatocele

Condition analysis:
Diagnosis can be made using chest X-ray; the lesion shows up as a small, round area filled with air. Computed tomography can give a more detailed understanding of the lesion. Differential diagnoses, other conditions that could cause similar symptoms as Pneumatocele, include lung cancer, tuberculosis, and a lung abscess in the setting of Hyper IgE syndrome (aka Job's syndrome) or on its own, often caused by Staphylococcus aureus infection during cystic fibrosis.

Instructions:
Pathophysiology: Since the 1950s, multiple theories have been proposed as to the exact mechanism of pneumatocele formation; however, the exact mechanism remains controversial.

Carrey suggested that the initial event is inflammation and narrowing of the bronchus, leading to the formation of an endobronchial ball valve. Ultimately, this bronchial obstruction leads to distal dilatation of the bronchi and alveoli. In 1951, Conway proposed that a peribronchial abscess forms and subsequently ruptures its contents into the bronchial lumen. This also acts similarly to a ball-valve obstruction in the bronchus and leads to distal dilatation. In 1972, Boisset concluded that pneumatoceles are caused by bronchial inflammation that ruptures the bronchiolar walls and causes the formation of "air corridors."  Air dissects down these corridors to the pleura and forms pneumatoceles, a form of subpleural emphysema.