[Sentinel node navigation surgery in melanoma and non-melanoma malignant skin tumor]

Sentinel node biopsy (SNB) has been performed for melanomas by many researchers since Morton's report in 1992. The technique has been well discussed, however, there have been only few reports about the application of SNB for treatment strategy of melanoma patients. Besides, we have not yet enough information of the clinical significance of SNB for non-melanoma malignant skin tumors. In this paper, we report two new findings of SNB for melanoma patients from the results of a multi-institutional study of SNB in 203 cases of melanoma. Firstly, the incidence of metastasis in non-sentinel node (non-SN) is less than 1% if no metastasis in SN; the identification rate of SN was 97.5%, the false negative rate was 0.98%, and correct diagnosis rate was 99.0%. Secondly, the incidence of metastasis in non-SN is less than 36.4% when patients had pSN 1 or pSN 2 metastasis. That means total removal of lymphnode metastasis can be achieved in 63.6% patients with lymphnode metastasis through SNB. Finally, we studied the usefulness of SNB on 71 cases of non-melanoma malignant skin tumors, and found the SN concept was also applicable for squamous cell carcinoma or invasive case of genital Paget's disease (Paget's carcinoma). Especially, we believe SNB for patients with Paget's carcinoma is as useful as for melanoma patients according our results of 25 cases; the identification rate of SN was 97.6%, the false negative rate was 0%, and correct diagnosis rate was 100%. SNB should be applied for patients with Paget's carcinoma as a diagnostic method of lymphnode metastasis and to determine the indication of lymphnode dissection, and its usefulness must be analyzed in the near future.