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.