Nesidioblastosis coexisting with islet cell tumor and intraductal papillary mucinous hyperplasia

A coexisting of intraductal papillary mucinous hyperplasia (IPMH) and islet cell tumor with nesidioblastosis of the pancreas in a 51-year-old man is r eported. All of the clinical data indicated an insulinoma. A distal pancrea tectomy was performed. A discrete mass measuring 1.9 x 2.0 cm was grossly i dentified in the tail of the pancreas. There were no other gross lesions. A n islet cell tumor with nesidioblastosis was confirmed by immunostains and ultrastructural study. in addition, an IPMH was found that involved mainly branches of the pancreatic duct. The islet cell tumor and IPMH were topogra phically separated; however, there was a histologically intimate relationsh ip between the nesidioblastosis and the IPMH. These findings indicate that the IPMH may have derived from autocrine and paracrine influences on the ex isting duct epithelial cells. To the best of our knowledge, this is the fir st report of nesidioblastosis coexisting with islet cell tumor and IPMH.