Acute acalculous cholecystitis simulating Mirizzi syndrome: a very rare condition.

Mirizzi syndrome, a rare complication of chronic cholelithiasis, is caused by an impacted stone in the cystic duct or the neck of the gallbladder. Patients present with abdominal pain, fever, and obstructive jaundice. The cholangiographic finding is a smooth stricture caused by lateral compression of the common hepatic duct. A similar appearance on cholangiogram can result from carcinoma of the gallbladder, carcinoma of the cystic duct, or hilar adenopathy. Acute acalculous cholecystitis simulating Mirizzi syndrome is extremely rare. This is the report of such a case in which marked inflammatory changes around the neck of the gallbladder likely caused significant mechanical obstruction of the common hepatic duct.