What is the gold standard surgical procedure for a patient with an ill-defined hilar mass encasing the common hepatic and cystic duct, showing diffusion restriction, high signal intensity on T2, low signal intensity on T1 with progressive enhancement, and extending into the area of junction of pancreatic and common bile ducts, resulting in mild pancreatic duct dilatation?

Gold Standard Surgical Procedure for Perihilar Cholangiocarcinoma (Klatskin Tumor)

The gold standard surgical procedure for this patient with a perihilar mass encasing the common hepatic and cystic ducts is hilar resection with en bloc major hepatectomy (extended right or left hepatectomy including caudate lobectomy) combined with extrahepatic bile duct excision and regional lymphadenectomy. 1

Rationale for This Approach

The imaging findings describe a perihilar cholangiocarcinoma (Klatskin tumor) based on:

• Ill-defined hilar mass (2.6 cm) encasing common hepatic and cystic ducts
• Progressive enhancement pattern with T2 hyperintensity and diffusion restriction
• Extension to the pancreaticobiliary junction
• Intrahepatic bile duct dilatation (left-sided predominance)
• CBD stent already in place 1, 2

Specific Surgical Components

Major Hepatectomy with Caudate Resection

• Extended hepatectomy (right or left lobe) including caudate lobectomy is strongly recommended for stage 3-4 hilar cholangiocarcinomas, as this approach increases resectability, achieves R0 margins, and has been associated with higher 5-year survival rates (20-40%) 1
• The caudate lobe must be resected because perihilar tumors frequently invade caudate bile ducts and the tumor's location at the biliary confluence makes caudate involvement highly likely 1, 2
• Left-sided intrahepatic bile duct dilatation suggests the tumor may be extending toward the left hepatic duct, which would favor extended right hepatectomy 2

Complete Extrahepatic Bile Duct Excision

• En bloc resection of the entire extrahepatic biliary tree is mandatory to achieve negative margins 1
• The tumor extends to the pancreaticobiliary junction, requiring excision down to this level 1

Regional Lymphadenectomy

• Comprehensive lymph node dissection of porta hepatis, gastrohepatic ligament, and retroduodenal nodes is required for accurate staging and potential survival benefit 1

Biliary Reconstruction

• Roux-en-Y hepaticojejunostomy to the remaining intrahepatic bile ducts with frozen section confirmation of negative ductal margins 1, 2

Preoperative Considerations

Portal Vein Embolization

• Preoperative portal vein embolization should be performed if estimated remnant liver volume is <25% to reduce postoperative liver dysfunction 1
• This increases the future liver remnant volume and improves surgical safety 1

Staging Laparoscopy

• Laparoscopy is recommended before definitive resection to identify occult peritoneal or liver metastases that would preclude curative resection 1, 2

Biliary Drainage Controversy

• The existing CBD stent indicates biliary drainage has been performed 1
• While controversy exists about preoperative biliary drainage risks versus benefits, panel consensus suggests it should be considered before major hepatectomy, though this must be discussed with specialized hepatobiliary surgeons 1

Critical Pitfalls to Avoid

Inadequate Hepatic Resection

• Simple bile duct excision without major hepatectomy is inadequate for perihilar cholangiocarcinoma and results in positive margins and poor survival 1, 2
• The tumor's encasement of hilar structures mandates en bloc hepatic resection 2

Failure to Resect Caudate Lobe

• Omitting caudate lobectomy significantly increases the risk of R1 resection due to direct tumor extension into caudate bile ducts 1, 2

Inadequate Lymphadenectomy

• Regional lymph node involvement significantly impacts prognosis and adjuvant therapy decisions 1

Additional Findings Requiring Attention

Gallbladder Management

• The distended gallbladder with multiple stones should be removed en bloc with the specimen 1
• Cholecystectomy is part of the standard hilar resection 1

Gastric Fundal Cystic Lesion

• The 1.2 cm cystic lesion near the gastric fundus (likely gastric diverticulum or lymphangioma) is incidental and does not alter the primary surgical approach 1
• This can be evaluated separately and does not require intervention unless symptomatic 1

Expected Outcomes

• Five-year survival rates of 20-40% are reported for perihilar cholangiocarcinoma after complete R0 resection with major hepatectomy 1
• R0 resection is the only potentially curative treatment and the primary determinant of long-term survival 1, 2
• Even with aggressive surgery, local recurrence rates remain high (52%), making complete resection with negative margins paramount 1

This patient requires referral to a specialized hepatobiliary surgical center with expertise in complex hilar resections, as surgical outcomes are significantly better at high-volume centers. 1, 2