Benign Gall Bladder Mass (Xanthogranulomatous Cholecystitis) Masquerading as Gall Bladder Cancer

84 year gentleman presented to LPC Mumbai with 2 months history of vague abdominal discomfort and no significant clinical findings. A USG of the abdomen done prior to visit to LPC Mumbai showed gall stones with an infiltrative mass lesion in GB fossa. His work up at LPC Mumbai showed normal CBC, BUN, Creatinine, Liver Function Tests, PT & INR, blood sugars & CA19-9 levels. Triple phase CT scan of abdomen & pelvis, & MRCP with contrast MRI suggested a gall bladder mass with gallstones, normal CBD & IHBR. Mass was slightly invading segment 4b &5 & possibly involving the hepatic flexure of the colon. Pancreas & duodenum was normal. The enhancement pattern of the mass after IV contrast was indicative of a malignancy with a small possibility of xanthogranulomatous cholecystitis (XGC). There was no evidence of biliary obstruction (dilated IHBR CHD or CBD).Right hepatic artery (RHA) & right anterior portal vein (RAPV) was slightly adhered to the mass. CT volumetry of liver showed left lobe volume approximately 35% of standard liver volume (SLV) & right lobe volume approximately 65% of SLV.