Which biliary pathology is defined by obstruction caused by a gallstone in the cystic duct compressing the common hepatic duct?

Which biliary pathology is defined by obstruction caused by a gallstone in the cystic duct compressing the common hepatic duct?

• A. Cholecystitis
• B. Gallstone ileus
• C. Mirizzi Syndrome
• D. Bouveret syndrome

Answer: (C)

Mirizzi syndrome describes obstruction of the biliary system from external compression of the common hepatic duct by a gallstone stuck in the cystic duct or at the gallbladder neck. This exact setup—an impacted stone in the cystic duct compressing the common hepatic duct—blocks bile flow from the liver, leading to obstructive jaundice and often dilation of the intrahepatic ducts. On ultrasound you’d look for a gallstone at the cystic duct or Hartmann’s pouch with narrowing or compression of the common hepatic duct and possible proximal ductal dilation; the CBD may be normal or only mildly dilated, depending on the stage, and the gallbladder is typically involved. This differs from the others: gallstone ileus and Bouveret syndrome are downstream bowel obstructions caused by a gallstone entering the GI tract via a biliary-enteric fistula, not a biliary duct obstruction. Cholecystitis is gallbladder inflammation from cystic duct obstruction but does not involve external compression of the common hepatic duct by a cystic duct stone.

Mirizzi syndrome describes obstruction of the biliary system from external compression of the common hepatic duct by a gallstone stuck in the cystic duct or at the gallbladder neck. This exact setup—an impacted stone in the cystic duct compressing the common hepatic duct—blocks bile flow from the liver, leading to obstructive jaundice and often dilation of the intrahepatic ducts. On ultrasound you’d look for a gallstone at the cystic duct or Hartmann’s pouch with narrowing or compression of the common hepatic duct and possible proximal ductal dilation; the CBD may be normal or only mildly dilated, depending on the stage, and the gallbladder is typically involved.

This differs from the others: gallstone ileus and Bouveret syndrome are downstream bowel obstructions caused by a gallstone entering the GI tract via a biliary-enteric fistula, not a biliary duct obstruction. Cholecystitis is gallbladder inflammation from cystic duct obstruction but does not involve external compression of the common hepatic duct by a cystic duct stone.