Figure 31b. Mirizzi syndrome mimicking a Klatskin tumor. (a) Sagittal US scan through the porta hepatis shows a large gallstone (S) in the region of the common bile duct and common hepatic duct dilating the latter (cd). GB = gallbladder. (b) Subcostal US scan obtained cephalad to a shows an infiltrative "mass" (arrowheads) obstructing the proximal right and left bile ducts, thereby mimicking a Klatskin tumor. (c) Endoscopic retrograde cholangiopancreatogram helps confirm the diagnosis. Inflammatory tissue was proved at surgery.