Patients with clinically node negative extremity Merkel cell carcinoma: The importance of identifying and treating patients with microscopic nodal metastases.

OBJECTIVES

To review the management of patients with Merkel cell carcinoma (MCC) of the distal arm or leg.

METHODS

The files of 27 patients with clinically node-negative extremity-located MCC treated between 1993 and 2007 at Westmead Hospital, Sydney, were reviewed.

RESULTS

The median age was 79 (range 48-91 years); there were 16 women and 11 men. The median follow up was 36 months. Eighteen patients had a below knee primary and nine had a below elbow primary. None had previous treatment of draining nodes. Most (26/27) underwent excision and 10 of the 27 received adjuvant local radiotherapy. The median lesion size was 19 mm (range 10-30 mm). In total 55% relapsed with most occurrences in the ipsilateral nodes of the axilla or groin. Median time to relapse was 5.5 months. Overall survival at two and five years was 68% and 57%, respectively.

CONCLUSIONS

Patients with extremity MCC experience a high rate of nodal relapse. Recently published evidence supports a survival benefit to identifying patients with microscopic nodal metastases. As en bloc primary and nodal treatment is not possible, and elective nodal treatment is likely to over-treat many patients, sentinel lymph node biopsy is a useful adjunct to current investigations and should be recommended.