Lymphatic mapping and sentinel node biopsy in Merkel's cell carcinoma.

Aim: The purpose of this study was to determine the predictive value of lymphatic mapping with selective lymphadenectomy in patients with Merkel's cell carcinoma.
Methods: Eight patients with biopsy proven Merkel's cell carcinoma underwent sentinel node biopsy. Lymphoscintigraphy was performed the day before surgery following intradermal injection of 74-111MBq of 99mTc-nanocolloid divided into four doses around the biopsy scar. Dynamic and static images were obtained.
Results: At least one sentinel node was visualized in all patients. The sentinel node was intra-operatively identified with the aid of a hand-held gamma probe in all cases and patent blue dye in six out of eight cases. During surgery, all sentinel nodes were successfully harvested. Metastatic cell deposits were subsequently identified in three patients (37.5%) and they underwent regional lymphadenectomy. No additional involved lymph nodes were identified. No recurrence has been reported in a median follow-up of 4.6 years (range: 8 months-10 years).
Conclusions: In conclusion, sentinel node biopsy in patients with Merkel's cell carcinoma appears to be a reliable staging technique.