Transmural invasion of hepatic flexure of colon causing cholecystocolic fistula by aggressive gallbladder carcinoma

Spontaneous enterobiliary fistulae are a complication of biliary disease or a disease of adjacent structures. Cholecystocolic fistulae are rare in relation to gallbladder carcinoma (GBC). Previous reports have presented images showing subtle findings suggestive of cholecystocolic fistula. We report the unusual spread and rare images of a case of cholecystocolicfistula,to highlight the aggressive nature of GBC and findings of gross transmural invasion of the colonic wall. The images acquired in all three planes define the anatomical and pathological extent conclusively. There are a higher number of GBC cases across the geographic belt of North India compared to the West. In this case, the patient's pathology was extensive and unresectable, and therefore palliative and supportive care wasadvised.