Pneumatocele rupture

A pneumatocele is a cavity in the lung parenchyma filled with air that may result from pulmonary trauma during mechanical ventilation.Gas-filled, or air-filled lesions in bone are known as pneumocysts. When a pneumocyst is found in a bone it is called an intraosseous pneumocyst, or a vertebral pneumocyst when found in a vertebra. [Source: Wikipedia ]