Intraductal papillary mucinous neoplasms of the pancreas: An increasingly recognized clinicopathologic entity

Objective To assess the authors' experience with intraductal papillary muci nous neoplasms of the pancreas (IPMNs). Summary Background Data Intraductal papillary mucinous neoplasms of the pan creas are being recognized with increasing frequency. Methods All patients who underwent pancreatic resection for an IPMN at the Johns Hopkins Hospital between January 1987 and December 2000 were studied. The data were compared with those of 702 concurrent patients with infiltra ting ductal adenocarcinoma of the pancreas not associated with an IPMN rese cted by pancreaticoduodenectomy. Results In the 13-year time period, 60 patients underwent pancreatic resect ion for IPMNs, with 40 patients undergoing resection in the past 3 years. M ean age at presentation was 67.4 +/- 1.4 years. The most common presenting symptom in patients with IPMNs was abdominal pain (59%). Most IPMNs were in the head of the pancreas or diffusely involved the gland, with 70% being r esected via pancreaticoduodenectomy, 22% via total pancreatectomy, and 8% v ia distal pancreatectomy. Twenty-two patients (37%) had IPMNs with an assoc iated infiltrating adenocarcinoma. In a subset of IPMNs immunohistochemical ly stained for the Dpc4 protein (n = 50), all of the intraductal or noninva sive components strongly expressed Dpc4, whereas 84% of associated infiltra ting cancers expressed Dpc4. The 5-year survival rate for all patients with IPMNs (n = 60) was 57%. Conclusion Intraductal papillary mucinous neoplasms represent a distinct cl inicopathologic entity being recognized with increasing frequency. IPMNs ar e clinically, histologically, and genetically disparate from pancreatic duc tal adenocarcinomas. The distinct clinical features, the presumably long in situ or noninvasive phase, and the good long-term survival of patients wit h IPMNs offer a unique opportunity for early diagnosis, curative resection, and further studies of the molecular genetics and natural history of these unusual neoplasms.