Pseudocyst of ectopic pancreas of the duodenal wall masquerading as malignant cystic tumor of pancreas.

We report a patient who underwent pancreaticoduodenectomy for a cystic lesion in the region of the pancreatic head and duodenum. Preoperatively, we had suspected a malignant lesion; however, it turned out to be ectopic pancreatic tissue in the duodenal wall, with the changes of chronic pancreatitis and pseudocyst formation. With this report we seek to highlight the rarity of this particular pathologic combination and the difficulties in its correct preoperative diagnosis and management.