Prevalence of incidental intraductal papillary mucinous neoplasm: Bologna experience

Background: Several studies evaluated intraductal papillary mucinous neoplasms (IPMNs) prevalence using selected patients. The “true” prevalence of incidental IPMN still remain unknown. Aim: To evaluate the prevalence of IPMN in a non selected population and its correlation with other diseases. Methods: Data from 6.357 abdominal ultrasonography (US) performed from 2012 to 2015 were collected. The inclusion criteria were: age > 18 years and absence of pancreatic disease. All patients with suspected IPMN were further investigated with magnetic resonance cholangio-pancreatography (MRCP). The prevalence of IPMN was calculated. The association with others disease were studied with multivariate analysis. Results: A total of 240 pancreatic cystic lesions were detected. MRCP confirmed that 224 (93.3%) were IPMN. The prevalence of IPMN was 3.5% (224/6357): IPMN type II and type I/III had a prevalence of 3.3 % and 0.2 %, respectively. At univariate analysis, IPMN were more frequent in female patients (P< 0.001), age between 40-50 or >70 years (P< 0.001), patients whit chronic disorder (P=0.007) as well as cirrhosis (P=0.011), non cirrhotic liver disease (P< 0.001) or inflammatory bowel disease (P=0.003). Multivariate analysis showed that the only factors related to IPMN were female gender (OR 2.4; 95% CI 1.8-3.3; P< 0.001) and age between 40-50 years (OR 5.0; 95% CI 2.3-10.7; P< 0.001) and over 70 years (OR 2.1; 95% CI 1.5-3.0; P< 0.001). Conclusions: The prevalence of IPMNs in a non-selected population was 3.5%. The factors related to this prevalence were gender and age. No association with chronic or neoplastic disease was found.