Imaging and Screening of Cancer of the Gallbladder and Bile Ducts.

Biliary cancers include gallbladder cancer (GBC) and cholangiocarcinoma (CCA). GBC may appear as a mass replacing the gallbladder, thickened gallbladder wall, or polypoid lesion in the gallbladder. Gallbladder polyps with low risk of GBC (eg, 6- to 10-mm polyps without other risk factors) are screened with sonography. In general, polyps smaller than 5 mm are ignored and those larger than 10 mm require surgical consideration. Screening for CCA is less well-established. On imaging, CCA may be divided into mass-forming, periductal infiltrating, and intraductal types. This review discusses the current state of screening and diagnosis of GBC and CCA.