The purpose of this study is to determine whether we can consistently identify the first lymph node (the "sentinel node") draining your melanoma.

The issue of elective lymph node dissection (LND) in the management of melanoma patients with clinically negative nodes remains controversial. The concept of elective LND is attractive because it provides the opportunity to detect and remove occult micrometastases before they become clinically apparent. Numerous retrospective analyses have consistently shown a 15-20% long term survival advantage in patients undergoing elective LND who are found to have positive nodes, compared to those undergoing therapeutic LND for clinically positive nodes. The majority of patients undergoing elective LND however, do not have lymph node involvement, and the impact of removal of these negative nodes on the survival of these patients is unknown. The substantial morbidity of these procedures has led to the conduct of a number of important prospective randomized trials designed to define the impact of elective LND on the survival of patients with clinically node negative melanoma. In 1982, the World Health Organization reported on the end results of 553

The primary objective of this protocol is to establish the feasibility of lymph node mapping, using preoperative lymphoscintigraphy and intraoperative blue dye injection to detect the sentinel node in patients at risk for regional lymph node metastasis from their primary melanoma.

Inclusion Criteria:

• primary melanomas Clark III and Breslow thickness > 1 mm, or Clark IV-V and any Breslow thickness
• clinically negative regional nodes

Exclusion Criteria:

• previous definitive wide local excision of the primary melanoma with skin graft
• an inflammatory lesion in the area of the primary melanoma that is likely to drain to the same nodal basin
• pregnancy

Patients with primary melanomas Clark III and Breslow thickness > 1 mm, or Clark IV-V and any Breslow thickness, and clinically negative regional nodes. Patients with a resectable solitary intransit metastasis and clinically negative nodes will be considered for entry on to this protocol on an individual basis.