[A case of perforated xanthogranulomatous cholecystitis presenting as biloma].

Xanthogranulomatous cholecystitis is an unusual inflammatory disease of the gallbladder characterized by severe proliferative fibrosis and the accumulation of lipid-laden macrophages in areas of destructive inflammation. Its macroscopic appearance may occasionally be confused with gallbladder carcinoma. We present a case of perforated xanthogranulomatous cholecystitis presenting as biloma. An 80-year-old woman was referred to our hospital with a 1-week history of abdominal pain and febrile sensation. Abdominal CT showed a biloma in the subhepatic area. The follow-up CT showed that the biloma increased in size. Therefore, ultrasonography-guided aspiration was performed. The aspirated fluid/serum bilirubin ratio was greater than 5, which was strongly suggestive of bile leakage complicated by perforated cholecystitis. She underwent a laparoscopic cholecystectomy with cyst aspiration and adhesiolysis. A histological diagnosis of perforated xanthogranulomatous cholecystitis was made.