Dermatomyositis associated with thyroid cancer.

We describe herein dermatomyositis (DM) associated with thyroid cancer in a 54-year-old woman. She was resistant to corticosteroids at first, but removal of the coexisting cancer resulted in improvement of DM. Reports on the association of DM with thyroid cancer are very few. However, recently, increasing incidence of thyroid cancer is pointed out. It is thought that increasing incidence reflects increased detection of subclinical disease due to increased diagnostic scrutiny, not an increase in the true occurrence of thyroid cancer. Thus, DM associated with thyroid cancer may be more frequent than we generally expected. We recommend that thyroid studies should be included in cancer investigations, particularly in DM cases resistant to corticosteroids.