1. Intrahepatic Bile Ducts Liver diagram differentiating intrahepatic bile ducts from extrahepatic bile ducts and showing a mass-forming type of intrahepatic cholangiocarcinoma. The intrahepatic bile ducts extend from the periphery of the liver and include the right and left hepatic ducts. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer

2. Intrahepatic Bile Ducts Segmental anatomy of the liver. The eight segments of the liver are numbered clockwise in a frontal plane. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer

3. Intrahepatic Bile Ducts Lymph node drainage patterns for intrahepatic carcinomas vary with tumor location within the liver. Segments 2 and 3 drain to lymph nodes along the lesser curvature of the stomach and subsequently to the celiac nodal basin. Intrahepatic cholangiocarcinomas of the right liver (segments 5-8) may preferentially drain to hilar lymph nodes and subsequently to caval and periaortic lymph nodes. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer

4. Intrahepatic Bile Ducts T1 is defined as a solitary tumor without vascular invasion, regardless of size. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer

5. Intrahepatic Bile Ducts All solitary tumors with vascular invasion and confined to the liver are classified as T2a. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer

6. Intrahepatic Bile Ducts Multiple tumors confined to the liver, with or without vascular invasion, are classified as T2b. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer

7. Intrahepatic Bile Ducts Two views of T3: tumor with perforation of visceral peritoneum (left of dotted line); tumor directly invading adjacent organs (right of dotted line, tumor invades stomach). Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer

8. Intrahepatic Bile Ducts Periductal infiltrating tumors exhibit diffuse longitudinal growth pattern along the intrahepatic bile ducts on both gross and microscopic examination. T4 includes diffuse periductal infiltrating tumors (A) and mixed mass-forming and periductal infiltrating tumors (B). Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer

9. Intrahepatic Bile Ducts N1 is defined as metastasis to regional lymph nodes. Compton, C.C., Byrd, D.R., et al., Editors. AJCC CancerStaging Atlas, 2nd Edition. New York: Springer, 2012. ©American Joint Committee on Cancer