Dermatomyositis and multiple malignancies in a patient treated with methotrexate

Dermatomyositis (DM) has been linked to internal malignancy but this relationship is quite variable in respect to tumor type and time sequence. The occurrence of multiple cancers in an individual with DM is rare. Immunosuppressive agents, particularly methotrexate have been used increasingly in corticosteroid resistant cases or for their corticosteroid sparing effects. These agents have not been implicated in the development of malignancy in patients with DM. A patient with a uterine adenocarcinoma developed DM that despite tumor removal was not responsive to corticosteroids. She was successfully treated with methotrexate for 18 months. She has subsequently developed an adenocarcinoma of the breast. The relationship of malignancy and DM as well as the role of methotrexate in the development of the second primary will be discussed.