Mirizzi syndrome with an unusual aberrant hepatic duct fistula: a case report.

Mirizzi syndrome (MS) is a rare complication of chronic cholelithiasis, which is always caused by a calculus in the cystic duct or neck of the gallbladder, resulting in mechanical compression of common bile duct and the gallbladder. It is clinically characterized by abdominal pain, fever, as well as obstructive jaundice. During cholecystectomy, MS is seen as a dangerous adherent and inflammatory tissue in the area of Calot's triangle. In the general population, aberrant right posterior hepatic duct, one of the causes of bile duct injury during duct surgery, is present in 4.8%-8.4% of people. Herein we report a rare case of a 76-year-old female patient, with hepatolithiasis of right posterior lobe and cholecysto-aberrant right posterior hepatic duct fistula. This is a special type of MS; however, interestingly, she did not have any symptoms, and the disease was found by physical examination incidentally. This case highlights another situation, namely, there may be difficulty in diagnosing MS and dissecting for operation. Therefore, to avoid the complication associated with this special situation, the surgeons need to diagnose carefully and adopt an optimal treatment strategy.