Radiolocalization of the sentinel lymph node in Merkel cell carcinoma: a clinical analysis of seven cases.

Overview

Merkel cell carcinoma (MCC) is a rare cutaneous skin lesion with a variable but often aggressive clinical course. Patient survival correlates with nodal status and the presence of distant metastases. The histologic status of the sentinel lymph node consistently correlates with the incidence of regional lymphatic metastases in other dermal malignancies. The technique of radiolocalization and surgical resection of the sentinel lymph node using an intraoperative gamma probe is used to guide clinical management in these patients. We report on seven cases of MCC managed utilizing this technique. Four patients had negative sentinel nodes and no other nodal disease at completion lymphadenectomy (n = 2) or clinical follow-up (n = 2) and currently remain disease free. Two patients had a positive sentinel node but no other positive lymph nodes at completion lymphadenectomy; one of them developed regional recurrence. One patient with a positive sentinel node and six additional positive nodes developed extensive nodal disease and systemic recurrence during radiotherapy and expired of MCC. Our results suggest that the sentinel node was identified and removed successfully using radiolocalization making this technique useful in the staging and therapy of patients with MCC.