A small fraction of solid mass in the head of the pancreas are inflammatory rather neoplastic in origin. The failure to recognize the true nature of a solid tumor in the head of pancreas may lead to an incorrect treatment strategy. This is a report of a patient with clinical history of pancreatic cancer which computed tomography showed a mass in the head of the pancreas with radiologic characteristics of malignancy. The patient underwent exploratory laparotomy with the finding of a mass in the head of the pancreas. The inflammatory palpable characteristic of the mass led to a intraoperative biopsy to confirm the preoperative diagnosis. With the benign result of the biopsy, the final diagnosis was duodenal ulcer which penetrates in the pancreatic parenchyma.