Case report of a cystic dystrophia appearing in an ectopic pancreas. The clinical diagnosis was preoperatively suspected by the findings of CT scan revealing a tumor located in the wall of the duodenum and by the data of MRI indicating its cystic and fibrotic structure. A focus of reacting pancreatitis was found in the vicinity of the cystic dystrophia while the remaining pancreas was normal. The surgical treatment was a duodenopancreatectomy, justified by the potential risks of complications.