Reply to “Letter to Editor: Main-duct Intraductal Papillary Mucinous Neoplasm
We thank Prof Del Chiaro and Prof Schulick for their comment on our work and their agreement on our observation that main-duct intraductal papillary mucinous neoplasm (IPMN) with a duct diameter of 5 to 9 mm already represents a finding with a relevant malignant potential.1 It is certainly important to point out the differences between the 2013 European Expert Consensus Statement on Cystic Tumors of the Pancreas 2 and the current Fukuoka guidelines for these lesions established by the International Association of Pancreatology (IAP) in 2012.3 We regret for not having included the European Guidelines in the discussion of our present article. With regard to the conception of our study, we aimed to primarily evaluate the accuracy of the IAP guidelines, and therefore chose the 5 to 9 mm main-duct IPMN group as the lowering of the threshold for the definition of main-duct IPMN was one of the most important modifications in the 2012 guidelines compared with the original Sendai IAP recommendations 2006.4 The European consensus does not explicitly state the 5 mm threshold for surgery in main-duct IPMN alone, but gives a clear recommendation for surgery in mixed-type lesions with a main-duct diameter more than 6 mm. This recommendation is strongly supported by our observations and the consensus statement that malignancy may occur in main-duct IPMN with a duct diameter less than 10 mm. As stated by Prof Del Chiaro and Prof Schulick, our main goal must be to perform IPMN resection before malignancy occurs and to avoid resection in harmless branch-duct IPMN. We did not address the topic of branch-duct IPMN in our present article as this has been a major topic in previous publication from our group.5 With regard to the management of main-duct and mixed-type IPMN, we absolutely agree with the concept of a more aggressive surgical approach that is in line with the European consensus statement. Our data support this, and as the management of IPMN is still under debate and represents a continuous learning process, we hope to have given a relevant contribution that may be useful for future guideline and consensus meetings.