Ampullary Adenoma and Hepatic Inflammatory Pseudotumor Mimicking Malignancies on 18F-FDG PET/CT

We report a rare case of ampullary tubulovillous adenoma with secondary jaundice and hepatic inflammatory pseudotumor mimicking malignancies on 18 F-FDG PET/CT. A 68-year-old woman presented with fever, jaundice and abdominal pain. Serum tumor markers (CEA, AFP, CA19-9, CA125, and CA242) were normal, except for a mild elevation CA72-4. 18 F-FDG PET/CT revealed biliary obstruction, hypermetabolic foci in the descending duodenum, and a hepatic mass, initially suggesting ampullary adenocarcinoma with hepatic metastasis. Post-surgery pathology confirmed ampullary tubulovillous adenoma and hepatic inflammatory pseudotumor.