A case of pseudotumorous pancreatitis that presented unique pancreatoscopic findings with the peroral electronic pancreatoscope

Abstract
A 49-year-old man was admitted to Hospital of Kyoto Prefectural University of Medicine complaining of epigastralgia and jaundice. There was a tumor (approximately 30 mm) in the pancreatic head on ultrasound, computed tomography and magnetic resonance imaging. Endoscopic retrograde cholangiopancreatography revealed a stenosis of the main pancreatic duct in the head of the pancreas. Pancreatoscopy with the peroral electronic pancreatoscope (PEPS) was performed to differentiate between pseudotumorous pancreatitis (PTP) and pancreatic carcinoma. The PEPS showed non-erosive erythematous mucosa around the stenosis and this unique finding was different from that of pancreatic carcinoma. Pylorus-preserving pancreatoduodenectomy was performed under the possible diagnosis of carcinoma. As a result, the diagnosis of PTP was confirmed histopathologically. At present, the diagnosis of PTP is difficult because of similar findings with carcinoma in various imaging procedures. However, we consider that detailed observation and accurate morphologic assessment of the main pancreatic duct with the PEPS has the possibility of differentiating PTP from pancreatic carcinoma.