The patients consisted of a 60-year-old woman and a 72-year-old man with no significant symptoms, who were both referred to the hospital due to the presence of large pancreatic tumors. They underwent F-18 FDG PET/CT and subsequently a pancreaticoduodenectomy and acinar cell carcinoma in the pancreas was proven histopathologically. In one case, the tumor consisted of a solid component presenting intense FDG uptake and necrotic tissue. In another case, the tumor consisted of cystic and papillary components presenting with weak FDG uptake. This report thus documents 2 cases of acinar cell carcinoma that showed contrasting histopathologic and F-18 FDG PET/CT findings.