Predictors of the Presence of Concomitant Invasive Ductal Carcinoma in Intraductal Papillary Mucinous Neoplasm of the Pancreas

Objective: Invasive ductal carcinoma (DC) of the pancreas arising as an independent lesion in association with intraductal papillary mucinous neoplasm (IPMN) has occasionally been reported. However, clinicopathological features related to the presence of DC in patients with IPMN remain largely unknown. The purpose of the present study was to determine the factors predicting the presence of concomitant DC in those with IPMN. Materials and Methods: We retrospectively reviewed the clinicopathological data of a consecutive series of 236 patients with IPMN treated by surgical resection or followed up at our institution between January 1987 and June 2008. In an attempt to identify predictors for the presence of DC, clinicopathological variables were compared between IPMN patients with concomitant DC and those without concomitant DC. Results: Of 236 patients with IPMN, concomitant DC was detected synchronously or metachronously in 22 patients (9.3%). All the 22 IPMNs were of branch duct type and histological grades of 12 resected IPMNs were adenoma (n = 8) and borderline (n = 4). Multivariate analysis revealed 2 significant predictive factors for the presence of DC in IPMN, including worsening diabetes mellitus (P < 0.001) and an abnormal serum CA 19-9 level (P = 0.024). Conclusion: In view of the high prevalence of DC careful inspection of the entire pancreatic gland is necessary for early detection of DC in patients with branch duct IPMNs, especially when worsening diabetes mellitus and an abnormal serum CA 19-9 level are manifested.