The Great Imitator: A Case Report of Mirizzi Syndrome Misdiagnosed as Cholangiocarcinoma Bismuth Type II.

Background: An unusual complication of gallstone diseases is Mirizzi syndrome. This disorder is characterized by jaundice, fever and right upper quadrant pain. It is defined by an obstruction of the common hepatic duct due to an extrinsic compression from a stone in the gallbladder infundibulum or the cystic duct. It should be identified as soon as possible in order to prevent complications, notably biliary sepsis.This disorder can sometimes mimic the symptoms of cholangiocarcinoma (CCA). Case summary: We present the case of a 69 years old male presenting for painless jaundice and dark urine of 1 week duration. Upon several abdominal imaging and laboratory examinations, the patient was diagnosed with CCA Klatskin tumor type II. The patient was referred for a bile duct resection with caudate lobectomy and Roux-en-Y hepticojejunostomy. However, during surgery, the patient was found to have 2 large stones at the base of gallbladder, obstructing the common bile duct, directing the diagnosis towards Mirizzi syndrome (MS).The uniqueness of the case lies in the patient's presentation, as well as the thorough investigation which were in favor of the Klatskin tumor. Conclusion: MS is a very rare complication of gallstone diseases. It can sometimes present similarly to CCA. Therefore, a more precise and accurate diagnostic tools should be employed in order to be able to differentiate between these two entities.