The association between dermatomyositis (DM) and malignancy has been recognized for a long time. Dermatomyositis has been assessed as a paraneoplastic syndrome. The pathogenesis of this co-morbidity is poorly understood. Dermatomyositis precedes the neoplasm in some cases, in other it may occur together with the neoplasm and sometimes the neoplasm may occur first. The higher risk of the development of the neoplasm occurs during the first five years of the diagnosis of DM. Primary tumours occur in ovaries, lungs, gastrointestinal tract, breast and lymphonodes. The prognosis of the neoplasm development depends on age. The incidence of neoplasm in adults is higher than in young persons. The peak incidence occurs between the ages of 40 and 69 years. We present a case report of a 60-year-old woman with the diagnosis of DM and breast cancer and coinciding female genital tract cancers. The patient underwent the surgery and chemotherapy. The patient was observed for 11 months after completion of treatment and she was in good condition. The relapse of DM symptoms was the reason for cancer rescreening and the metastases of ovarian cancer to subcutaneous tissue of the abdomen were found.