Melanoma thickness and histology predict sentinel lymph node status

Background: It remains unclear which patients with melanoma will benefit most from lymphatic mapping and sentinel lymphadenectomy. The purpose of this study is to determine whether primary melanoma histopathologic features could be applied to predict sentinel node status. Methods: One hundred twelve patients underwent sentinel node biopsy between May 1995 and August 1999. Reported histologic features were assessed for predictive value by univariate and multivariate logistic regression. Results: The sentinel node was located successfully in 105 of the 112 patients (94%). Twenty-one of these 105 patients (20%) had sentinel nodes that were positive for metastatic disease. Multivariate analyses revealed that tumor thickness greater than 1.5 mm (P = 0.01), ulceration (P <0.01), and lymphovascular invasion (P = 0.05) predicted the presence of micrometastases. Conclusions: The presence of unfavorable histopathology such as ulceration and lymphovascular invasion may identify a group of patients with thin melanomas who would benefit from sentinel lymphadenectomy.