Klatskin Tumor
Klatskin tumor is an extra-hepatic cholangiocarcinoma (CCA, see this term) arising in the junction of the main right or left hepatic ducts to form the common hepatic duct.
Epidemiology
The prevalence is unknown.
Clinical description
Klatskin tumors occur in the hepatic duct bifurcation, usually presenting in the 5th to 7th decade of life and are seen slightly more frequently in males (1.3:1 male to female ratio). Patients are usually asymptomatic until advanced stages of the disease where jaundice is the principle manifestation. Abdominal pain, weight loss and malaise are other manifestations experienced by some patients. Metastasis to regional lymph nodes is frequent. It can spread from the pericholedochal nodes in the hepatoduodenal ligament to the posteriorsuperior area around the pancreatic head, common hepatic artery and portal vein.
Etiology
In 90% of cases Klatskin tumors occur sporadically but certain risk factors have been associated with the disease. Risk factors include primary sclerosing cholangitis (see this term), secondary sclerosing cholangitis, chronic typhoid carriage, parasitic infections (with Opisthochis viverrini and Clonorchis sinensis), exposure to thorotrast (x-ray contrast medium) and choledochal cysts, all of which cause chronic biliary inflammation.
Diagnostic methods
Diagnosis is suspected on clinical and laboratory findings. Serum carbohydrate antigen (CA) 19-9 is a glycoprotein tumor marker found to be elevated in most cases of Klatskin tumors. Increased levels of alkaline phosphate (ALP), conjugated bilirubin and gamma-glutamyl transpeptidase (GGT) are also noted. Abdominal imaging, visualization of the biliary tree and biopsies of the lesion are necessary to make the diagnosis. Endosonography (EUS) guided fine needle aspiration (FNA) of hilar lymph nodes is the most useful tool in the diagnosis and staging of Klatskin tumors. Brush cytology and percutaneous biopsies have a low sensitivity for diagnosis. Ultrasound, and contrast enhanced helical computerized computed tomography (CT) can be used in visualizing the extent of disease.
Differential diagnosis
Autoimmune cholangitis and primary biliary non-Hodgkin's lymphoma are differential diagnoses of Klatskin tumors.
Management and treatment
Relief of biliary blockage and resection of disease are the main goals of treatment. As Klatskin tumors are typically resistant to chemotherapy and radiotherapy, surgical resection of the tumor is the only curative treatment but it is not always an option in those patients with widespread metastasis. Surgical resection involves a liver resection with caudate lobectomy in order to achieve a higher chance of negative resection margins. Palliative treatment involves the placement of plastic or metallic biliary stents. Percutaneous transhepatic catheters provide the best access for palliation of inoperable Klatskin tumors. Unresectable Klatskin tumors are treated with radiotherapy and/or chemotherapy. Gemcitabine combined with cisplatin therapy has been recognized as a standard treatment for unresectable biliary tract cancers including Klatskin tumors.
Prognosis
As Klatskin tumors are often only discovered at an advanced stage, the prognosis is quite poor with five year survival rates after surgery ranging from 25-30% and 0% in unresectable tumors.