This study plans to test the pathologic complete response (pCR) rate of the combination biotherapy regimen consisting of nivolumab plus ipilimumab versus nivolumab alone in patients with advanced but operable melanoma. Evaluation of the presence of tumor-infiltrating CD8+ T cells as well as that of PDL1 expression and IDO expression will be associated with clinical response (pathologic and/or radiologic). The study will test the radiologic/clinical preoperative response rate, recurrence free survival (RFS) and overall survival (OS). It will evaluate the safety of neoadjuvant nivolumab and neoadjuvant nivolumab-ipilimumab. Up to 66 patients will be randomized in 1:1 ratio.