Metastatic Merkel cell carcinoma to the soft tissues of the lower back.

Merkel cell carcinoma (MCC) is a rare primary cutaneous neuroendocrine carcinoma. It has a propensity for both locoregional and distant recurrence despite treatment. We describe the case of a 51-year-old man diagnosed with MCC of the left forehead. At 14 months post surgery and adjuvant radiotherapy he developed an isolated deposit of metastatic MCC in the paraspinal soft tissues of his lower back. This atypical site of metastatic disease was treated with radiotherapy and combination chemotherapy. Atypical and isolated sites of metastatic MCC, although infrequently reported, highlight the often bizarre nature of this aggressive skin cancer. Treatment in such cases needs to be individualized.