Mirizzi syndrome caused by xanthogranulomatous cholecystitis: report of a case.

Xanthogranulomatous cholecystitis (XGC) is a rare inflammatory disease of the gallbladder. In severe cases, inflammation extends to adjacent structures, and XGC is sometimes confused with a malignant neoplasm. We recently diagnosed XGC as the preoperative cause of Mirizzi syndrome in a patient based on the clinical course. The patient was admitted because of obstructive jaundice, with gallbladder carcinoma as the suspected cause. The gallbladder was swollen with gallstones and the serum level of carbohydrate antigen 19-9 (CA19-9) was 3070 U/ml at admission. A percutaneous transhepatic cholangiodrainage (PTCD) was done, and the common hepatic duct as well as the right and left hepatic ducts were found to be obstructed. Later, the CA19-9 level and swelling of the gallbladder decreased and the obstruction of the bile ducts disappeared. A cholecystectomy was performed and the intraoperative pathohistological diagnosis of chronic cholecystitis was made from frozen sections. The pathohistological diagnosis of XGC was made from paraffin-embedded sections. Mirizzi syndrome such as that seen in our patient is a rare complication of XGC. XGC occasionally causes extensive inflammation; thus, performing a conventional cholecystectomy can be unsafe. However, in our opinion, a total, not subtotal, cholecystectomy should be done whenever possible because the incidence of gallbladder carcinoma accompanied with XGC is higher than that with ordinary cholecystitis or gallstones.