Intraductal papillary mucinous neoplasms - Predictors of malignant and invasive pathology

Objective: Determine whether size and other preoperative parameters predict malignant or invasive intraductal papillary mucinous neoplasia (lPMN). Summary Background Data: From 1991 to 2006, 150 patients underwent 156 operations for IPMN. Methods: Prospectively collected, retrospective review of a single academic institution's experience. All preoperative parameters including a detailed radiologic-based classification of IPMN type, location, distribution, size, number, cytology, and mural nodularity were correlated with IPMN pathology. Results: Malignant IPMN was present in 32% of cases, whereas 19% of cases were invasive. IPMN type and main pancreatic duct diameter were significant predictors of malignant IPMN (P < 0.001). Side- branch lesion number was negatively associated with invasive IPMN (P = 0.03). Side-branch size, location, and distribution did not predict lPMN pathology. The presence of mural nodules was associated with malignant and invasive IPMN (P < 0.001; P < 0.02). Atypical cytopathology was significantly associated with malignant and invasive IPMN (P < 0.001; P < 0.001). Multivariate analysis demonstrated mural nodularity and atypical cytopathology were predictive of malignancy and/or invasion in branch-type IPMN. Conclusions: To lower the rate of invasive pathology, surgery should be recommended for fit patients with main-duct IPMN and for branch-duct IPMN with mural nodularity or positive cytology irrespective of location, distribution, or size.