Outcome of patients with melanoma and histologically negative sentinel lymph nodes

Hypothesis: Patients with melanoma and histologically negative sentinel lym ph nodes identified by lymphatic mapping have a very good prognosis. Design: Cohort study with follow-up information obtained from medical recor ds and telephone interviews. Setting and Patients: Of all patients with cutaneous melanoma who underwent intraoperative sentinel lymph node mapping between November 15, 1993, and April 18, 1997, at the Massachusetts General Hospital, Boston, 89 were foun d to have no evidence of melanoma in their sentinel nodes. Forty-six lesion s (51%) were on an extremity and 44 (49%) were of axial location. The media n tumor thickness was 1.8 mm (range, 0.36-12.0,mm) and 11 tumors (12%) were ulcerated. Interventions: Patients underwent intraoperative sentinel lymph node mappin g with lymphazurin and radiolabeled sulfur colloid. Sentinel lymph nodes we re analyzed by standard hematoxylin-eosin staining. Only 2 patients receive d adjuvant therapy following wide excision of the primary lesion. Main Outcome Measures: Site of initial recurrence and time to initial recur rence. Results: The median follow-up for all patients was 23 months (range, 2-54 m onths). Eleven patients (12%) developed melanoma recurrences, and 78 (88%) patients remain disease free. Regional lymph nodes were the initial site of recurrence in 7 (8%) of 89 patients, and 7 (7%) of 106 mapped basins. Four patients had recurrence without involvement of regional lymph nodes: 2 wit h distant metastases and 2 with in transit metastases. The median time to r ecurrence was 12 months (range, 2-35 months). Sentinel lymph nodes were rea nalyzed using serial sections and immunoperoxidase stains in 7 patients wit h recurrence and metastatic melanoma was identified in 3 (43%). Conclusions: The risk for melanoma recurrence is relatively low in patients with histologically negative sentinel nodes identified by lymphatic mappin g. Longer follow-up will improve our understanding of the prognostic value of this procedure.