This is an monocenter, single arm, clinical investigation that evaluate the impact of the method on the objective response rate (ORR) of visceral lesions undergoing electrochemotherapy. Electrochemotherapy is a well-defined method for the treatment of cutaneous and subcutaneous metastases of different tumor histotypes. Although still limited, the various experiences in the treatment of visceral localizations, particularly in liver metastases from colorectal cancer are promising and show that electrochemotherapy is a safe treatment, even in the case of lesions near large vessels or nerves. The investigators therefore propose a clinical investigation with a Medical Device according to EU Regulation 745/2017, using electrochemotherapy (Cliniporator) with bleomycin for the treatment of visceral, primary or secondary, unresectable localizations, with percutaneous or intraoperative technique (laparoscopic or laparotomy), as needed.