Fig. 8

Pathological findings. a Medium magnification image: abundant mucus and cell mass floating in the mucus lake are recognized. b High-magnification image: cells with densely stained and swollen irregular nuclei form clumps and float with some connectivity. This is a finding of colloid cancer. c Portal vein: the portal vein (white arrowheads) was full of tumor, and the small vessel around the tumor (black arrowheads) was also full of tumor. d The high-magnification image of c (rectangle). There was no distinct evidence of the tumor directly involving into the portal vein