Preoperative predictors of malignancy in pancreatic intraductal papillary mucinous neoplasms.

HYPOTHESIS Malignant intraductal papillary mucinous neoplasms (IPMNs) can be predicted before surgery. DESIGN Retrospective review of a prospectively collected database. SETTING Academic, urban, tertiary care hospital. PATIENTS Sixty-four consecutive patients with a pathological diagnosis of IPMN. INTERVENTIONS All 64 patients underwent surgical intervention for IPMN between December 8, 1988, and October 16, 2002. MAIN OUTCOME MEASURES Reliable predictors of malignancy. RESULTS The 64 patients underwent 69 operations: 39 pancreaticoduodenectomies, 18 distal pancreatectomies, 7 total pancreatectomies, 4 neck and/or body pancreatectomies, and 1 cystgastrostomy with pancreatic biopsy. Twenty-three of 69 specimens were malignant-12 in situ (high-grade dysplasia) and 11 invasive. In a univariate analysis of 12 clinical signs or symptoms recorded, diabetes mellitus and jaundice showed a significant association with malignancy of IPMN. Of 24 serum chemistry studies, hematologic studies, and tumor marker analyses (in serum, bile, and pancreatic fluid), elevation of serum alkaline phosphatase and glucose levels showed correlation with malignancy. Computed tomography, ultrasound, and endoscopic retrograde cholangiopancreatography findings did not distinguish between benign and malignant tumors. Atypia on preoperative cytologic analysis was specific for malignancy (93%) but lacked the same degree of sensitivity (40% in situ, 91% invasive, and 67% overall). CONCLUSIONS Malignancy of IPMNs is suggested by new-onset diabetes mellitus, jaundice, and elevations in serum glucose or alkaline phosphatase levels. Atypia on preoperative cytologic testing is the finding most predictive of malignancy. The absence of these features does not predict benign disease. These findings may help guide patient and physician decision making.