Diagnostic-therapeutic management of bile duct cancer

Table 1 Eighth edition of the TNM classification of the AJCC/UICC (2017-2018)[30] - Intrahepatic cholangiocarcinoma

Primary tumor (pT)	Regional lymph nodes (pN)	Distant metastasis (pM)	Stage grouping
TX: Primary tumor cannot be assessed	NX: Regional lymph nodes cannot be assessed		Stage 0: Tis N0 M0; Stage IA: T1a N0 M0; Stage IB: T1b N0 M0; Stage IIA: T2 N0 M0; Stage IIIA: T3 N0 M0; Stage IIIB: T4 N0 M0; any T N1 M0; Stage IV: any T any N M1
T0: No evidence of primary tumor	N0: No regional lymph node metastasis	M0: No distant metastasis
Tis: Carcinoma in situ (intraductal tumor)
T1: Solitary tumor without vascular invasion T1a: Solitary tumor ≤ 5 cm without vascular invasion; T1b: Solitary tumor > 5 cm without vascular invasion	N1: Regional lymph node metástasis	M1: Distant metástasis
T2: Solitary tumor with intrahepatic vascular invasion or multiple tumors, with or without vascular invasion
T3: Tumor perforating the visceral peritoneum
T4: Tumor involving local extrahepatic structures by direct invasión
Note: Tumor growth patterns (mass forming versus periductal) are no longer part of staging criteria but should still be reported	Notes: Regional lymph nodes depend on tumor site. For left sided lesions, regional nodes include inferior phrenic, hilar and gastrohepatic lymph nodes. For right sided lesions, regional nodes include hilar, periduodenal and peripancreatic lymph nodes.

Table 2 Eighth edition of the TNM classification of the AJCC/UICC (2017-2018)[30] - Perihilar cholangiocarcinoma

Primary tumor (pT)	Regional lymph nodes (pN)	Distant metastasis (pM)	Stage grouping
TX: Primary tumor cannot be assessed	NX: Regional lymph nodes cannot be assessed		Stage 0: Tis N0 M0; Stage I: T1 N0 M0; Stage II: T2a-b N0 M0; Stage IIIA: T3 N0 M0; Stage IIIB: T4 N0 M0; Stage IIIC: any T N1 M0; Stage IVA: any T N2 M0; Stage IVB: any T any N M1
T0: No evidence of primary tumor	N0: No regional lymph node metastasis	M0: No distant metastasis
Tis: Carcinoma in situ/high grade dysplasia
T1: Tumor confined to the bile duct, with extension up to the muscle layer or fibrous tissue	N1: One to three positive lymph nodes typically involving the hilar, cystic duct, common bile duct (choledochal), hepatic artery, posterior pancreatoduodenal and portal vein lymph nodes	M1: Distant metástasis
T2: Tumor invades beyond the wall of the bile duct to surrounding adipose tissue or tumor invades adjacent hepatic parenchyma; T2a: Tumor invades beyond the wall of the bile duct to surrounding adipose tissue; T2b: Tumor invades adjacent hepatic parenchyma	N2: Four or more positive lymph nodes from the sites described for N1
T3: Tumor invades unilateral branches of the portal vein or hepatic artery
T4: Tumor invades the main portal vein or its branches bilaterally or the common hepatic artery; or unilateral second order biliary radicles with contralateral portal vein or hepatic artery involvement

Table 3 Eighth edition of the TNM classification of the AJCC/UICC (2017-2018)[30] - Distal cholangiocarcinoma

Primary tumor (pT)	Regional lymph nodes (pN)	Distant metastasis (pM)	Stage grouping
TX: Primary tumor cannot be assessed	NX: Regional lymph nodes cannot be assessed		Stage 0: Tis N0 M0; Stage I: T1 N0 M0; Stage IIA: T1 N1 M0 or T2 N0 M0; Stage IIB: T2 N1 M0 or T3 N0-1 M0; Stage IIIA: T1-3 N2 M0; Stage IIIB: T4 N0-2 M0
T0: No evidence of primary tumor	N0: No regional lymph node metastasis	M0: No distant metastasis
Tis: Carcinoma in situ / high grade dysplasia
T1: tumor invades the bile duct wall with a depth less than 5 mm	N1: Metastasis in one to three regional lymph nodes	M1: Distant metástasis
T2: Tumor invades the bile duct wall with a depth of 5 - 12 mm	N2: Metastasis in four or more regional lymph nodes
T3: Tumor invades the bile duct wall with a depth greater than 12 mm
T4: Tumor invades the celiac axis, superior mesenteric artery or common hepatic artery