[Resection of main duct and mixed type IPMN ≥5 mm].

The incidence of cystic pancreatic lesions is steadily increasing due to the technical advances in imaging. Within the group of cystic pancreatic lesions intraductal papillary mucinous neoplasms (IPMNs) depict an important entity. Due to a possible progression to malignancy the clinical strategy has to be well chosen. For primary diagnostic work-up imaging by magnetic resonance imaging (MRI) with MR cholangiopancreatography (MRCP) and computed tomography (CT) scanning is recommended. Additional information can be gained by endosonography and a biopsy of the cystic lesion, allowing analysis of biomarkers, such as GNAS and KRAS mutation as wells as NLR. These can help to differentiate between IPMN and other cystic lesions although the clinical importance for the diagnosis of main duct (MD) and mixed IPMN is limited. The current guidelines (Fukuoka and EU guidelines) recommend resection of MD and mixed IPMN following oncological standards. For the definition of MD-IPMN, a duct dilatation between 5-10 mm is needed when following the current guidelines; however, current publications claim an even lower cut-off of ≥5 mm due to the risk of malignant progression. Intraoperative frozen sections are recommended to evaluate the margins status and extended resection is recommended for residual high-grade dysplasia. Surveillance of potentially at risk patients is recommended at regular intervals of 6-12 months while patients with malignant IPMN should be followed according to pancreatic cancer protocols. A screening for extrapancreatic malignancy is not indicated.