“…These included 7 patients with osteogenic sarcoma, 7 with germinal tumors, 3 with uterine leiomyosarcoma, 2 with endometrial carcinoma, 2 with synovial cell sarcoma, 2 with lymphoma, and 1 each with Wilm's tumor, thymoma, small cell lung cancer, adenocarcinoma from an unknown primary, and breast cancer. [3][4][5][6][7][8] The actual mechanism of the complicating pneumothorax in primary and metastatic lung cancer is not completely understood, but the pathophysiology would depend on the particular tumor involved. For example, in primary lung cancer the SSP may be produced either by the pathological lung abnormalities that occur secondary to smoking, or by progression of the tumor, causing rupture of an ischemic primary lesion into the pleural space.…”