The most common sites of gastric carcinoma metastasis are liver, peritoneum, lung, and bone. Metastasis to the common bile duct (CBD) is rare thus we present a patient with recently diagnosed gastric adenocarcinoma who presented with findings of CBD obstruction and was found to have metastasis of gastric adenocarcinoma to the distal CBD, which was initially thought to be gallstone related. The patient is a 91yo Caucasian male with recently diagnosed gastric adenocarcinoma, A. Fib, CHF and HTN who presented with complaints of fever, chills, abdominal pain and generalized fatigue for past week. He reported weight loss and loss of appetite. Physical exam was generally unremarkable with no overt evidence of jaundice or scleral icterus. No tenderness to palpation of the abdomen. Initial laboratory studies revealed total bilirubin of 3.1, alkaline phosphatase of 313, AST of 139 and ALT of 149. CT abdomen showed thickening of the gastric antrum compatible with the known history of gastric adenocarcinoma and also a filling defect within the periampullary common bile duct with mild intrahepatic and extrahepatic biliary ductal dilation. MRCP was also obtained which further noted intrahepatic and extrahepatic ductal dilation up to 1.8cm and a periampullary enhancing filling defect in the distal CBD measuring approximately 6mm. Given these findings, the patient underwent ERCP during which a cholangiogram showed a filling defect in the distal CBD of 10mm in diameter, along with dilation of common hepatic duct of 12 mm. Multiple balloon sweeps were performed and two small stones and sludge were extracted. Also during this process, the large filling defect that was seen on the cholangiogram was also extracted out of the duct and was found actually to be a polypoid distal CBD mass instead of a stone. The extracted specimen was biopsied for histology and a biliary stent was placed at the conclusion of the procedure. The patient tolerated the procedure well and his symptoms and laboratory values improved. The CBD mass biopsies were reviewed in conjunction with the previous gastric mass biopsies, which noted the two specimens exhibited similar histomorphological features compatible with gastric adenocarcinoma. Conclusion: Although metastases to the CBD are rare, this case illustrates that clinicians should take metastatic lesions into consideration when laboratory and imaging studies are suggestive of CBD obstruction in patients with primary gastric adenocarcinoma.Figure: Malignant Gastic Carcinoma in Gastric Antrum.Figure: Cholangiogram demonstrating filling defects in the distal common bile duct (arrow) and subsequent dilation of the main bile duct.Figure: Polypoid mass extracted during sweep of the biliary tree.