Traumatic Pneumatocele

Pathophysiology:  Acute, generally high energy trauma to the chest wall leading to small airways collapse and regional “explosion” of the subtended lung.  Results in regional areas of contusion, bleeding and cavitation with the injured lung communicating with the damaged small airways.

Clinical Clues:  Look for more serious associated thoracic trauma (e.g. aortic injuries, esophageal laceration, tracheal or bronchial trauma, flail chest, tension pneumothorax, large hemothorax etc…) which need immediate diagnosis and treatment.

CXR Findings:

1. regional area of airspace disease with cavitation, may be multiple

2. associated thoracic trauma (e.g. rib fractures, pneumothorax, hemothorax etc…)

“Aunt Sophies”: gamut of cavitary lung disease

1. infections: granulomatous and CAP

2. tumour: primary and metastatic disease (squamous cell)

3. vasculitis (e.g. Wegener’s granulomatosis)

4. complicated bullous disease

5. infected bronchogenic cyst