Lymphatic Mapping and Sentinel Lymph Node Biopsy in the Management of Primary Cutaneous Melanoma: Report of a Single-centre Experience

Abstract

Lymphatic mapping and sentinel lymph node biopsy provide important prognostic data in patients with early stage melanoma and are crucial in guiding the management of the tumor. We report our experience with lymphatic mapping and sentinel lymph node biopsy in a group of patients with primary cutaneous melanoma and discuss recent concepts and controversies on its use. A total of 111 patients with stage I-II AJCC primary cutaneous melanoma underwent lymphatic mapping and sentinel lymph node biopsy from December 1999 through December 2004 using a standardized technique of preoperative lymphoscintigraphy and biopsy guided by blue dye injection in addition to a hand-held gamma probe. After removal, sentinel lymph nodes were submitted to serial sectioning and permanent preparations for histological and immunohistochemical examination. Complete lymph node dissection was performed only in patients with tumor-positive sentinel lymph nodes. Sentinel lymph nodes were identified and removed in all patients (detection rate of 100%), and metastases were found in 17 cases (15.3%). The incidence of metastasis in sentinel lymph nodes was 2.1%, 15.9%, 35.2%, and 41.6% for melanomas < or 1.0, 1.01-2.0, 2.01-4.0, and > 4.0 mm in thickness, respectively. Complete lymph node dissection was performed in 15 of 17 patients with positive sentinel lymph nodes, and metastases in non-sentinel lymph nodes were detected in only 2 cases (11.7%). Recurrences were more frequently observed in patients with a positive than in those with negative sentinel lymph node (41.1% vs. 5.3% at a median follow-up of 31.5 months, P < 0.001). The false-negative rate was 2.1%. Our study confirms that lymphatic mapping and sentinel lymph node biopsy allow accurate staging and yield relevant prognostic information in patients with early stage melanoma.