ENDOSCOPIC DIAGNOSIS OF INTRADUCTAL PAPILLARY MUCINOUS NEOPLASM USING PERORAL PANCREATOSCOPY WITH NARROW BAND IMAGING

A 77‐year‐old man was diagnosed with a pancreas cyst at another hospital. Abdominal ultrasonography revealed a cyst in the head of the pancreas and a small protrusion. These findings suggested intraductal papillary mucinous neoplasm. Cytologic finding of the pancreatic juice revealed a Class III lesion, and intraductal ultrasonography and peroral pancreatoscopy (PPS) were performed. An abnormal course of main pancreatic duct (MPD) prevented the insertion of an ultrasonography probe into the MPD, and PPS was performed. The mucosal surface of the MPD near the papillary area was normal, and narrow band imaging (NBI) clearly showed the vascular structure. When the PPS was inserted more deeply, many small protrusions were observed and NBI delineated the protrusions more clearly. Papillary protrusions were observed in the cyst, but NBI did not reveal any tumor vessels. These findings led to a diagnosis of benign intraductal papillary mucinous neoplasm lesion. Since then, follow‐up examinations have been made. Changes in the cyst and protrusion have not been observed.