Massive portal vein tumor thrombus from colorectal cancer without any metastatic nodules in the liver parenchyma: report of a case oleh Yasushi Rino, Manabu Shiozawa, Daisuke Inagaki, Amane Kanazawa, Soichiro Morinaga, Naoto Yamamoto, Nobuhiro Sugano, Makoto Akaike