A very frequent complication of advancing lung and breast cancer is pleural metastases, resulting in the formation of an effusion. If the effusion remains unchecked, it is not uncommon for the patient to die of pulmonary insufficiency. Although a malignant effusion usually portends a poor prognosis, the marked palliation that is achieved with control of the effusion justifies an aggressive approach to the problem. Various methods have been used in an effort to control malignant pleural effusion.6 All have had as their objectives removal of the fluid, reexpansion of the lung, and obliteration of the pleural space so that further fluid accumulation is impossible. Thoracentesis, alone or in combination with either intracavitary chemotherapy or various vesicants, has failed to give permanent control in the majority of patients. It is nearly impossible to remove all the pleural fluid and obtain full lung expansion with needle aspiration. As a result, pneumothorax,