Gallbladder Schematic of the gallbladder in relation to the liver and biliary tract. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, ©American Joint Committee on Cancer

Gallbladder Regional (N1) lymph nodes of the gallbladder are limited to the hepatic hilus (including nodes along the common bile duct, hepatic artery, portal vein, and cystic duct). Metastases to celiac, periduodenal, peripancreatic, and superior mesenteric artery lymph nodes are considered N2 disease. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, ©American Joint Committee on Cancer

Gallbladder Schematic of T1, showing the tumor invading the lamina propria (T1a) or muscle layer (T1b) of the gallbladder. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, ©American Joint Committee on Cancer

Gallbladder Two views of T2: tumor invading perimuscular connective tissue, with no invasion beyond serosa (illustration below dotted line) or into the liver (above dotted line). Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, ©American Joint Committee on Cancer

Gallbladder Two views of T3: tumor perforating the serosa (visceral peritoneum) (below the dotted line) and/or directly invading the liver (above the dotted line). Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, ©American Joint Committee on Cancer

Gallbladder T3 may also be defined as tumor invading one other adjacent organ or structure, such as the duodenum (as illustrated), or the stomach, colon, pancreas, omentum, or extrahepatic bile ducts. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, ©American Joint Committee on Cancer

Gallbladder T4 is defined as tumor invading main portal vein or hepatic artery. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, ©American Joint Committee on Cancer

Gallbladder T4 is defined as invading two or more extrahepatic organs or structures (here, colon and duodenum). Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, ©American Joint Committee on Cancer

Gallbladder N1 is defined as metastasis to hepatic hilar (regional) lymph nodes. N2 is defined as metastasis to periaortic, pericaval, superior mesenteric artery and/or celiac artery lymph nodes. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, ©American Joint Committee on Cancer