Metachronous intraductal papillary mucinous neoplasm with carcinoma in situ of the pancreas arising within a short interval: report of a case.

A 61-year-old man with an intraductal papillary mucinous neoplasm (IPMN) and carcinoma in situ (CIS) of the pancreatic body initially underwent a distal pancreatectomy. Postoperative follow-up included computed tomography (CT) and ultrasonography (US) every 6 months. Intraductal papillary mucinous neoplasm of the pancreatic head was diagnosed 17 months later using peroral pancreatoscopy (POPS) including a biopsy, revealing IPMN with highly dysplastic changes. A total pancreatectomy was therefore performed. The pathological examination revealed IPMN with CIS. The patient was discharged from the hospital and is doing well as of 1 year postoperatively. Although cautious surveillance seems mandatory, consensus has not yet been reached regarding postoperative surveillance. This report presents an unreported case of metachronously arising IPMN with CIS within a relatively early interval, thus suggesting that surveillance every 6 months is preferable to > or = 1 year. In addition, endoscopic US, endoscopic retrograde cholangiopancreatography, intraductal US, or POPS should be included in pathological examinations to avoid missing opportunities to treat lesions such as noninvasive IPMN with a good prognosis. Surgically indicated patients with noninvasive recurrence should therefore be strongly considered to undergo a total pancreatectomy.