Successful resection of liver metastasis detected by exacerbation of skin symptom in a patient with dermatomyositis accompanied by rectal cancer: a case report and literature review

BACKGROUND: Dermatomyositis (DM) is a rare syndrome that belongs to the group of idiopathic inflammatory myopathies. The association between DM and malignancy is well recognized, and the severity of DM symptoms has been linked to the progression of metastatic disease. CASE PRESENTATION: We report the case of a 42-year-old man that was diagnosed with dermatomyositis (DM) and rectal cancer. Proctectomy was performed, and DM symptoms were resolved postoperatively. One year and 9 months after the surgery, liver metastasis occurred accompanied by the exacerbation of DM symptom. Partial resection of the liver was performed, and postoperative course was uneventful. DM symptoms improved postoperatively, and no evidence of cancer recurrence or DM symptoms was observed 2 years after the second surgery. To date, few reports have described recurring cases of DM accompanied by colorectal cancer in detail. We reviewed four similar cases that were reported poor prognoses with treatment resistance. However, our case report demonstrates good long-term results with resection of metastatic lesion. CONCLUSIONS: It is important to check the exacerbation of DM symptoms, as this symptom sometimes preceded cancer relapse during the follow-up of our patient with DM and colorectal cancer.