Detection of lymph node metastases in malignant melanoma after identification of the sentinel lymph-node with preoperative lymphoscintigraphy and intraoperative radio-isotopic detection.

Objectives: The aim of this study was to evaluate the detection of the firs t lymph node draining the primary tumour site, using a radioisotopic mappin g alone and to determine whether a preoperative lymphoscintigraphy using te chnetium sulfur colloid and a hand-held gamma detecting probe could improve the detection of the sentinel lymph node (SLN) in melanoma. Patients and method: From January to December 1998, 36 patients with a cuta neous melanoma larger than 0,75 mm, stage 1 TNM were included in this prosp ective study. Mean Breslow was 1,85 mm. The distribution of melanoma was he ad and neck (n=9), trunk (n=7), upper extremities (n=4), lower extremities (n=16). Preoperative lymphoscintigram and intraoperative detection were use d. The first hot lymph node was supposed to be the SLN. Results: In all cases, a lymph node was found and nine patients had more th an one SLN (average number of SLN per patient: 1.25). Aberrant drainages we re found in seven patients (19.4%) : 1 in-transit lymph node, three paradox ical bassins, three bypasses). Four out of 36 patients had lymph node metas tases and underwent elective lymph node dissection. Conclusion: The radio-isotopic technique used alone for the identification of the SLN is efficient in melanoma with a 100% detection rate in this shor t series. (C) 2000 Editions scientifiques et medicales Elsevier.