MKI67 and neoplasm: NEC are characterized by a high proclivity for metastatic dissemination even in patients with clinically localized tumors, and some retrospective studies have confirmed that surgery alone is rarely curative.15,24,25 These tumors are characterized by the poor differentiation and the high Ki-67 proliferative index whose rate is related with the tumor aggressiveness and probably with the potential of metastatic dissemination.9 In our series, 75% of patients had a Ki-67 > 50% and 67% a Ki-67 > 80%.