Rapidly progressive myositis as the sole manifestation of a concurrent gastric carcinoma.

Inflammatory myopathies including polymyositis and dermatomyositis are autoimmune disorders presenting with characteristic muscle weakness. These diseases, especially dermatomyositis, have a well-known association with a wide variety of neoplasms including lung, breast, ovary and colon cancers. Here we report the case of a 58-year-old man who presented with a 3-week history of myositis and was simultaneously diagnosed with gastric cancer.