Selective lymphadenectomy: emerging role for lymphatic mapping and sentinel node biopsy in the management of early stage melanoma.

The percentage of melanoma patients diagnosed at an early stage is increasing. Many of these patients, particularly those with primary tumors thicker than 1.5 mm, harbor occult metastases in regional nodes and are eligible for regional lymphadenectomy as part of their primary management. Until the results of recently completed prospective randomized trials are available the role for elective lymphadenectomy in terms of survival benefit remains a controversial issue. A new technique, intraoperative lymphatic mapping and sentinel node biopsy, has emerged as a simple way to determine whether or not metastatic disease is present. An intradermal injection of a vital blue dye at the site of the primary tumor allows identification of a "sentinel" node in the regional basin. A study of 237 patients was recently reported by Morton et al. (Arch Surg 127:392-399, 1992; Surg Oncol Clin North Am 1:247-259, 1992) demonstrating that the sentinel node can be readily identified > 80% of the time and that histologic examination of the node results in at least a 95% accuracy rate in staging the nodal basin for metastases. Our present series substantiates the results of the original study. An international multicenter trial has been proposed to further confirm the accuracy and universal feasibility of this technique. Acceptance of this technique will lead to a selective approach to regional lymphadenectomy, as only patients with proven micrometastases will undergo lymph node dissections. This approach should satisfy both the advocates and the opponents of elective regional lymphadenectomy.