Applicability of the sentinel node technique to Merkel cell carcinoma

BACKGROUND. Merkel cell carcinoma (MCC) resembles malignant melanoma in several ways. Both are cutaneous lesions of the same embryonic origin. Both have an unpredictable biologic behavior, early regional lymph node involvement, early distant metastases, and high recurrence rate. OBJECTIVE. To apply the sentinel node technique described for melanoma to MCC in light of the common biologic features of these two tumors. METHODS. Preoperative lymphoscintigraphy, intraoperative lymphatic mapping, and sentinel node biopsy and frozen section histology were performed to guide the surgical treatment of three patients with MCC. RESULTS. Application of this approach in patients with MCC is feasible, reproducible, and seems reliable. CONCLUSION. The use of the sentinel node technique for MCC will reduce the number of unnecessary lymphadenectomies, will enable identification of microscopic metastases to lymph nodes, and will improve the stratification and accrual of patients into adjuvant treatment protocols. It may even lead to a survival benefit.