Tracheobronchial tumor cast formation and pneumothorax.

A 34-year-old white man was admitted to the hospital for progressive respiratory difficulty, recurrent left pneumothorax, and a diagnosis of aplastic left lung. Further evaluation, including bronchoscopy and CT scan, demonstrated a cast-forming tracheobronchial obstructing tumor. Surgical resection of the tumor through the left chest with left lower lobectomy resolved his symptomatology. Improved ventilation with an open airway led to expansion of the left upper lobe. The pathologic diagnosis remained controversial as to a definite designation and was primarily descriptive: spindle cell proliferation with myxoid and collagenized stromal benign tumor. However, the extent of this rubbery tumor cast and the ability to remove it intact illustrate the tenacity of the structure and the very unusual nature of a cast of the entire tracheobronchial system on the left side.