Pre- and intraoperative images. a-c) Ultrasonography (US) shows a highly echoic mass in the gallbladder. The size was φ30 mm. The widespread lesion showed irregular, gross progression, corresponding to gallbladder cancer. Because the outer layer of the gallbladder was clearly preserved (especially on intraoperative US), indicating Type B, tumor depth was estimated as extending to the muscularis propria. Computed tomography (CT) also shows a mass in the gallbladder, with no invasion to other organs. d) US shows multiple swollen lymph nodes in the hepatoduodenal ligament. e-g) CT shows swelling of not only lymph nodes at the hepatoduodenal ligament, but also para-aortic lymph nodes. h,i) Diffusion-weighted imaging (DWI) shows signal hyperintensity for the gallbladder mass, but signal hypointensity in all detected swollen lymph nodes.