Accuracy of EUS for detection of intraductal papillary mucinous tumor of the pancreas

Background: Patients with intraductal papillary mucinous tumors of the pancreas (IPMT) present with symptoms similar to those of chronic pancreatitis. This study assessed the accuracy of EUS for detection of IPMT and identified features that discriminate IPMT from chronic pancreatitis. Methods: EUS accuracy for detecting IPMT was determined with characteristic findings by endoscopic retrograde pancreatography as the reference standard. To determine EUS features characteristic of IPMT, EUS images from patients with IPMT were compared with those from patients (similar age, gender) with chronic pancreatitis. Results: Thirty-eight patients (23 men, 15 women; age range 40-90 years) with IPMT were identified between 1994 and 2001. For EUS, the sensitivity was 86%, specificity 99%, positive predictive value 78%, and negative predictive value 99% for detection of IPMT. When compared with patients with chronic pancreatitis, the EUS features of dilation of pancreatic duct (89% vs. 42%, p < 0.0001), cysts (45% vs. 11% p = 0.002), and pancreatic atrophy (32% vs. 3%, p = 0.002) were more common, whereas parenchymal features of chronic pancreatitis were less common with IPMT (21% vs. 97%, p < 0.0001). By multivariate analysis, the presence of no more than one parenchymal feature of chronic pancreatitis suggested the diagnosis of IPMT (odds ratio 43.84; 95% CI [4.13, 465.74]). Conclusions: EUS may be useful in the initial evaluation of patients suspected to have IPMT. Paucity of parenchymal features of chronic pancreatitis is important in differentiating IPMT from other causes of chronic pancreatitis.