Asymptomatic gangrenous cholecystitis diagnosed using contrast-enhanced ultrasonography in a patient with pancreatic cancer.

A 72-year-old female without abdominal symptoms visited our hospital for routine follow-up while undergoing pancreatic cancer treatment (using TS-1). Her vital signs were normal, and her abdomen was soft and non-tender. Blood test revealed elevated C-reactive protein levels with normal white blood cell count. Computed tomography was performed for follow-up of pancreatic cancer. Contrast-enhanced computed tomography showed partial discontinuity and irregular thickness of the gallbladder wall; however, a definitive diagnosis was not obtained due to unclear imaging. Contrast-enhanced transabdominal ultrasonography revealed intraluminal membranes in the gallbladder and a perfusion defect at the bottom, indicating gangrenous cholecystitis. Surgical resection was performed, and pathological examination showed severe necrosis of the gallbladder wall, consistent with the findings of contrast-enhanced transabdominal ultrasonography.