Multicentric recurrence of intraductal papillary neoplasm of bile duct after spontaneous detachment of primary tumor:A case report

BACKGROUND Intraductal papillary neoplasm of the bile duct(IPNB)rarely recurs in a multicentric manner.We encountered a patient with multiple recurrences of the gastric subtype of IPNB one year after spontaneous detachment of the primary tumor during peroral cholangioscopy(POCS).CASE SUMMARY A 68-year-old woman on maintenance hemodialysis because of lupus nephritis had several cardiovascular diseases and a pancreatic intraductal papillary mucinous neoplasm(IPMN).She was referred to our department for dilation of the common bile duct(CBD)and a tumor in the lumen,detected using ultrasonography.She had no complaints,and blood tests of hepatobiliary enzymes were normal.Magnetic resonance cholangiopancreatography(MRCP)showed a papillary tumor in the CBD with a filling defect detected using endoscopic retrograde cholangiography(ERC).Intraductal ultrasonography revealed a papillary tumor and stalk at the CBD.During POCS,the tumor spontaneously detached with its stalk into the CBD.Pathology showed low-intermediate nuclear atypia of the gastric subtype of IPNB.After 1 year,follow-up MRCP showed multiple tumors distributed from the left hepatic duct to the CBD.ERC and POCS showed multicentric tumors.She was alive without hepatobiliary symptoms at least two years after initial diagnosis of IPNB.CONCLUSION The patient experienced gastric subtype of IPNB without curative resection.Observation may be reasonable for patients with this subtype.