[A Case of Xanthogranulomatous Cholecystitis That Is Difficult to Distinguish from Advanced Gallbladder Cancer with Invasion of the Transverse Colon].

A 53-year-old woman was admitted to our hospital because of hepatic dysfunction found during a medical checkup. Cholecystitis was suspected, and unenhanced computed tomography (CT) was initially performed because she had bronchial asthma. However, a tumor-like lesion was seen at the bottom of the gallbladder. Contrast-enhanced CT was performed 3 weeks later, and the tumor-like lesion was enhanced and had increased in size. Endoscopic ultrasound fine-needle aspiration did not reveal any signs of malignancy. Colonoscopy revealed ulcerations in the transverse colon, and invasion from gallbladder cancer was suspected. Our preoperative diagnosis was xanthogranulomatous cholecystitis, but gallbladder cancer could not be excluded. Gallbladder bed resection and partial resection of the transverse colon were performed. Intraoperative frozen section analysis did not reveal any malignant findings; hence, we considered that lymph node dissection was unnecessary. Pathological examination confirmed xanthogranulomatous cholecystitis with abscess formation. In cases of surgery for xanthogranulomatous cholecystitis, it is important to consider that this condition could coexist with gallbladder cancer.