Pneumatocele

Excerpt

Pulmonary pneumatoceles also referred to as pseudocysts in the literature, are air-filled thin-walled cysts that are formed in lung interstitium. They can be single but are more often multiple. The term “pseudocyst” signifies a lack of an epithelial lining. Size can vary from greater than 1 cm in diameter to occupying entire hemithorax, with walls less than 4 mm and are of uniform thickness. Pneumatocele may or may not contain air-fluid levels. The lung apices are usually spared, but pneumatocele can occur anywhere in the thoracic cavity. In 1977, Fraser and Pare defined pneumatoceles are air-filled cavity occupying one-third of the lung volume. In trauma, it can be associated with pulmonary contusion, pneumothorax, and pneumomediastinum.

There is no such thing as para mediastinal pneumatocele or gas in the pulmonary ligament. Analysis of 4 case reports showed that it represent medial pneumothorax behind pulmonary ligament or posterior pneumomediastinum.

Heamatopneumatocele is characterized by air-fluid levels in post-traumatic settings and contains air and blood.

Cervical pneumatoceles are rare but been reported in the literature in infants and could mimic laryngocele resulting in diagnostic challenges.

Desquamative interstitial pneumonia can result in the formation of multiple pulmonary cysts. A resolution of the pneumatocele after treatment with cyclophosphamide is seen in a case report.