Two Cases of Lung Cancer Associated with Dermatomyositis

Two cases of lung cancer, histologically large cell carcinoma and squamous cell carcinoma associated with dermatomyositis were reported. In one case serum LDH, GOT and GPT level were high, and the LE test and antinuclear antibody were staining positive. In the other case there were abnormalities in the serum T -cell subset. In each case, dermatomyositis was well controlled by the resection of lung cancer or by the systemic chemotherapy which made the tumor shrink in size, without any steroid therapy. Primarily the presence of an autoimmune mechanism was suggested in the relationship between lung cancer and dermatomyositis.