Sample size: based on previous data from the investigators showing that 25% of patients with a Breslow's Thickness ≥ 1mm will have node or visceral metastasis. For an alpha threshold of 5% and a study power of 80%, with 5% of dropouts, with the hypothesis that 40% of apnea syndrome patients will metastasis versus 20% in the control group the study should include 83 patients in each group.