Spontaneous pneumothorax

Pneumothorax occurring secondary to pulmonary metastasis is rare. 

This mode of presentation occurs secondary to necrosis of subpleurally located metastases with the resultant bronchopleural fistula. 

Cavitating sarcoma is reported to present in this manner.

 In some instances, the sub pleural metastases are not sufficiently large enough to be recognized in x-rays and pneumothorax is the presenting manifestation.

Pneumothorax in a patient with subroentgenographic metastatic sarcoma.