Collaborative Stage

Note 1: For cases coded to primary site code C24.0 (extrahepatic bile ducts), code the subsite in which the tumor arose. This information will be used to determine which CS schemas will be used to assign T, N, M, and AJCC stage group.
Note 2: According to AJCC, perihilar tumors are defined as those located in the extrahepatic biliary tree proximal to the origin of the cystic duct. These represent 70-80% of extrahepatic bile duct tumors. Distal bile duct tumors are those arising between the junction of the cystic duct and the ampulla of Vater, including those arising in the intrapancreatic portion of the common bile duct. These represent 20-30% of extrahepatic bile duct tumors.

Code	Description	Schema
010	Perihilar bile duct(s) Proximal extrahepatic bile duct(s) Hepatic duct(s)	BileDuctsPerihilar
020	Stated as Klatskin tumor	BileDuctsPerihilar
030	Cystic bile duct; cystic duct	CysticDuct
040	Common bile duct Common duct, NOS	BileDuctsDistal
050	Diffuse involvement More than one subsite involved, subsite of origin not stated	BileDuctsPerihilar
060	Subsite of extrahepatic bile ducts not stated, but treated with combined hepatic and hilar resection	BileDuctsPerihilar
070	Subsite of extrahepatic bile ducts not stated, but treated with pancreaticoduodenectomy	BileDuctsDistal
100	OBSOLETE DATA RETAINED V0200 C24.0 - originally coded in CSv1	BileDuctsPerihilar
999	Subsite of extrahepatic bile ducts not stated and not classifiable in codes 050-070	BileDuctsPerihilar

CS Site-Specific Factor 25Schema Discriminator: Subsite of Extrahepatic Bile Ducts