Pancreatic Incidentalomas: High Rate of Potentially Malignant Tumors

BACKGROUND: Pancreatic incidentaloma (PI) is an increasingly common diagnosis that has received little attention. We characterized these tumors and compared them with symptomatic pancreatic tumors (nonincidentaloma [NI]). STUDY DESIGN: A retrospective database of 475 consecutive pancreatectomies that were performed from January 1995 to June 2007 at our institution was analyzed. Data for PI and NI patient cohorts were compared. RESULTS: Sixty-four PIs (13.5%) and 411 NIs (86.5%) were identified; 21% of pancreatic body and tail tumors versus 9% of tumors located in the pancreatic head were incidentally diagnosed (p = 0.001). Twenty-two PIs (34%) versus 278 NIs (67%) were malignant (p < 0.0001), 38 PIs (60%) were premalignant, and the remaining 4 (6%) had little or no risk for malignant progression. Intrapapillary mucinous Cystic tumor was the most common diagnosis in the PI group (23.4%, n = 15). Of these, 13.3% (n = 2) were invasive versus 40.6% (n = 15) in the NI group (p = 0.02). Likewise, pathologic features for ductal adenocarcinomas were more favorable in PI versus NI tumors. Overall, PI patients had prolonged median disease-specific survival: 145 versus 46 months (p = 0.001). Median disease-specific survival for PI versus NI patients treated for adenocarcinoma were 22 versus 19 months, respectively (p = 0.4); 5-year disease-specific survival for PI versus NI patients treated for intrapapillary mucinous cystic tumor/mucinous cystadenoma were 94% versus 68%, respectively (p = 0.07). CONCLUSIONS: Operation for PI is common, and a substantial proportion of these lesions might be malignant or premalignant. Resection of these early tumors in asymptomatic individuals is associated with improved survival, as compared with patients with symptomatic disease. (J Am Coll Surg 2009; 209:313-319. (C) 2009 by the American College of Surgeons)