PANCREATIC MUCINOUS DUCTAL ECTASIA AND INTRADUCTAL PAPILLARY NEOPLASMS - A SINGLE MALIGNANT CLINICOPATHOLOGICAL ENTITY

Objective The purpose of the study is to review a single institutional experience with mucinous ductal ectasia(MDE) and intraductal papillar y neoplasms (IPNs) and to compare the clinicopathologic features of th e two groups of tumors. Summary Background Data Mucinous ductal ectasi a and IPNs represent newly recognized categories of pancreatic exocrin e tumors, previously confused with pancreatic cystic neoplasms. The na tural history of MDE and IPN is not well understood, and it is unclear whether MDE and IPN represent two distinct tumors or the same clinico pathologic entity. Methods The authors reviewed the clinical presentat ion, treatment, histopathology, and outcomes of 23 patients diagnosed with MDE or IPN at their institution over the past 6 years. Results Th e mean age at presentation for the cohort of patients with MDE and IPN was 62.5 years. The prevalence of abdominal pain was 75%, jaundice 25 %, weight loss 42%, steatorrhea 37.5%, diabetes 37.5%, and history of pancreatitis 29%. Serum CA 19-9 levels ranged from 0 to 5350 units/mL with high levels reflecting advanced disease. There were no significan t differences between MDE and IPN with respect to these parameters. Bo th MDE and IPN comprised papillary villous epithelial neoplasms involv ing the main and large pancreatic ducts. The tumors ranged from a few millimeters in size to panductal and were distinguished easily from cy stic neoplasms in all cases. Invasive carcinoma was present in 11 (46% ) of 24 patients, carcinoma in situ in an additional 10 (42%) of 24 pa tients, and low grade dysplasia in the remaining 3 (12%) of 24 patient s. Mucinous ductal ectasia and IPN differed histopathologically only i n degree of mucin secretion and tumor location. Mucinous ductal ectasi a, but not IPN, was characteristically mucin-hypersecreting and more f requently involved the head of the gland than did IPN (11/16 vs. 1/8, p < 0.04). All patients were explored surgically and 20 (83%) of 24 of the tumors were resectable with frozen section control of the duct ma rgins (9 pancreatoduodenectomies, 4 distal pancreatectomies, 7 total p ancreatectomies). Despite the 88% prevalence of cancer, the overall su rvival at a mean follow-up of 21 months was 13 (87%) of 15 for MDE and 5 (71%) of 7 for IPN. Conclusions Intraductal papillary neoplasms wit h or without MDE represent a spectrum of main duct papillary tumors ra nging from adenoma to carcinoma with differing amounts of extracellula r mucin production. Malignant IPNs with or without MDE typically exhib it extensive intraductal growth but are slow to invade the periductal tissues and slow to metastasize. The majority of patients with these t umors have resectable disease and a favorable prognosis; endoscopic th erapy is inappropriate. The encompassing term intraductal papillary-mu cinous tumors is appropriate.