Pancreatic morphological abnormality that was challenging to differentiate from an ectopic pancreas: a case report

BACKGROUND: Protrusion of the lateral contour of the pancreatic head is a pancreatic morphological abnormality, which is known as rare shape atypia. We present a rare case of protrusion of the lateral contour of the pancreatic head, which was challenging to distinguish from an ectopic pancreas. CASE PRESENTATION: The patient was a 40-year-old man with a history of acute pancreatitis that occurred twice in the past. He complained of epigastric pain since the day before the visit; his blood workup showed high serum amylase level and a CT scan revealed a 25-mm-large mass with contrast effect from the anterior wall of the gastric pylorus to the duodenum and increased surrounding fatty tissue density. Endoscopic ultrasonography revealed a mass lesion in the gastric pylorus with continuity with the gastric wall and suspected partial continuity with the pancreatic head. Thus, the possibility of pancreatic morphological abnormality or an ectopic pancreas was considered. Following which, resection was attempted and intraoperative findings showed a wide extension of the pancreatic parenchyma from the pancreatic head to the anterior wall of the gastric pylorus to the duodenal bulb. Since the patient only had mild pancreatitis, the resection was judged to be too invasive and was completed by exploratory laparoscopy. CONCLUSIONS: Even if the findings on preoperative CT are suspicious for an ectopic pancreas or tumor, a pancreatic morphological abnormality, such as a protrusion of the lateral contour of the pancreatic head, should be included in the differential diagnosis.