Dermatomyositis associated with prostate adenocarcinoma with neuroendocrine differentiation.

Background: Although it is known that malignancies can be associated with dermatomyositis, there are few reports on dermatomyositis associated with prostate cancer with neuroendocrine differentiation.

Case Presentation: A 63-year-old man visited our hospital due to pollakiuria. High levels of PSA and NSE were observed, and prostate biopsy revealed an adenocarcinoma with neuroendocrine differentiation.