Malignant, nonfunctioning, well-differentiated pancreatic neuroendocrine tumor in a 56-year-old woman who underwent resection of a carcinoid tumor in the ileum 15 years ago and recently received a diagnosis of breast cancer. (a) Axial contrast-enhanced multidetector CT image shows a well-defined, enhancing, solid lesion (arrow) in the pancreatic tail. (b) Axial PET/CT image shows a lack of focal FDG uptake within the lesion. At pathologic analysis, the lesion was determined to be a well-differentiated malignant pancreatic neuroendocrine tumor.