Ectopic pancreas is defined as pancreatic tissue outside the normal location of the pancreas. It can be affected by the same complications as the orthotopic pancreas, such as adenocarcinoma. This extremely rare complication (only 14 published cases) may have a better prognosis that adenocarcinoma of an orthotopic pancreas. Endoscopic ultrasonography may be useful in the diagnosis of this disease. We report a case of malignancy of the duodenal wall originating in aberrant pancreatic tissue, and review the literature.