Radiological diagnosis and staging of hilar cholangiocarcinoma

Abstract

Core tip: Hilar cholangiocarcinoma is a rare malignant tumor arising from the epithelium of the bile ducts. Surgery is still the only chance of potentially curative treatment in patients with perihilar cholangiocarcinoma. Multidetector computed tomography, magnetic resonance imaging and magnetic resonance cholangiography are useful tools, both to diagnose and stage hilar cholangiocarcinoma. INTRODUCTIONCarcinomas of the extrahepatic biliary tree, commonly known as hilar cholangiocarcinoma (HCCA), Klatskin tumors or perihilar cholangiocarcinomas, are rare malignancies that account for up to 3% of all gastrointestinal cancers. With an incidence rate of 0.5-2.0 cases per 100000, it is estimated that there are between 2500 and 4000 new cases per year in the United States [1] .Although this tumor may potentially affect any location of the biliary tree, tumors involving the biliary confluence, left-hand drive (LHD) and right-hand drive (RHD) (true Klatskin tumors) are most common and account for 40%-60% of all cases. Around 2/3 of cholangiocarcinomas are hilar or extrahepatic and originate from the bile duct epithelium at the level of confluence AbstractHilar cholangiocarcinoma is a rare malignant tumor arising from the epithelium of the bile ducts. Surgery is still the only chance of potentially curative treatment in patients with perihilar cholangiocarcinoma. However, radical resection requires aggressive surgical strategies that should be tailored optimally according to the location, size and vascular invasion of the tumors. Accurate diagnosis and staging of these tumors is therefore critical for optimal treatment planning and for determining a prognosis. Multidetector computed tomography (MDCT), magnetic resonance imaging (MRI) and MR cholangiography are useful tools, both to diagnose and stage hilar cholangiocarcinoma. Modern imaging techniques allow accurate detection of the level of obstruction and the longitudinal and radial spread of the tumor. In addition, high-resolution MDCT and MR provide specific radiographic features to determine vascular involvement of anatomic structures, such as the hepatic artery or the portal vein, which are critical to decide the surgical strategy. Finally, radiological staging allows detection of patients with distant metastasis in the liver or peritoneum who will not benefit from a surgical approach.

Multimodality imaging of intrahepatic cholangiocarcinoma

“…They are usually T2 hyperintense and T1 hypointense (23). After contrast administration, a nodular, well-defined mass with intense delayed enhancement is often visible (49). The pattern of contrast enhancement is similar to the massforming subtype, with heterogeneous early enhancement that peaks on the delayed phase (8,49).…”

“…Ultrasound rarely allows direct visualization of piCCA, unless it is associated with mass formation. However, indirect signs such as alterations in biliary caliber may be sonographically visible (2,49). The sensitivity and specificity of ultrasound for diagnosing perihilar forms of cholangiocarcinoma are 89% and 80-95%, respectively (2).…”

“…Fast scanning times, thin collimation, and excellent spatial resolution allow improved visualization of the longitudinal and radial extension of the tumor (49).…”

“…Most of these tumors exhibit papillary growth characteristics and proliferate toward the lumen with preservation of the bile duct wall and absence of parenchymal extension (2,8). Preservation of the bile duct wall without extension into the surrounding liver parenchyma distinguish this morphologic subtype from the periductal-infiltrating and mass-forming subtypes (49).…”

CT Evaluation of Disease Pattern in Hilar Cholangiocarcinoma

“…In type I syndrome inflammation around common bile duct leads to stricture formation and thus mimics periductal-infiltrating type of cholangiocarcinoma. In type II syndrome there is cholecysto-biliary fistula [28]. Primary sclerosing cholangitis is characterized by diffuse cholangitis and progressive fibrosis of both intrahepatic and extrahepatic bile ducts.…”