Hilar Cholangiocarcinoma (Klatskin Tumour)

Hilar cholangiocarcinoma — also known as Klatskin tumour — is a malignancy arising from the epithelial cells of the extrahepatic bile ducts at or near the biliary confluence (the junction of the right and left hepatic ducts). It is the most common form of cholangiocarcinoma, accounting for 50–70% of all bile duct cancers. Hilar cholangiocarcinoma is classified by the Bismuth-Corlette system (Types I–IV) based on the extent of biliary involvement. Type IV lesions — involving both right and left hepatic duct radicles — are the most advanced and technically challenging. Risk factors include primary sclerosing cholangitis (PSC), biliary cysts (Caroli disease), hepatolithiasis, clonorchiasis, and exposure to thorotrast or dioxin.

Patients typically present with progressive obstructive jaundice, pale stools, dark urine, pruritus, and weight loss. Cholangitis (fever with rigors) may supervene if biliary obstruction is complicated by infection. Diagnosis requires high-quality MRI with MRCP to delineate biliary anatomy and tumour extent, CT for vascular involvement, and — when needed — ERCP or percutaneous transhepatic cholangiography (PTC) for biliary decompression and brushings/biopsy. CA 19-9 is an important serum marker. Staging must assess resectability: involvement of both hepatic arteries, main portal vein, or bilateral second-order bile ducts indicates unresectability in most cases.

Surgical resection is the only potentially curative treatment and requires extensive HPB expertise. Standard resection for hilar cholangiocarcinoma combines extrahepatic bile duct excision, caudate lobe (segment 1) resection, and major hepatectomy (usually right or extended right hepatectomy) to achieve negative resection margins (R0). Biliary continuity is restored with a Roux-en-Y hepaticojejunostomy. Preoperative portal vein embolisation is frequently required to augment the FLR. For unresectable disease, biliary stenting, photodynamic therapy, and systemic chemotherapy (gemcitabine-cisplatin, or immunotherapy combinations for MSI-H/IDH1-mutant tumours) are employed. Liver transplantation following neoadjuvant chemoradiation (Mayo Protocol) is an option for highly selected patients with unresectable hilar cholangiocarcinoma at specialist centres.