Dear Editor,

Based on a recent review with regard to recommendations for an intraductal papillary mucinous neoplasm (IPMN) ¹, we want to highlight the fact that different studies have limitations when identifying potentially life threatening branch-duct IPMN. Both the Fukuoka criteria published in 2017 ² and the American Gastroenterological Association guidelines in 2015 ³ have a high specificity and positive predictive values ^1,4 (Table 1). However, the lack of criteria for malignancy does not completely reduce the risk of high grade dysplasia (HGD) or invasive carcinoma (IC). The 5-year IC risk for IPMN without malignancy criteria is 2-3% ¹.

Table 1 The accuracy of malignancy criteria for IPMN according to retrospective studies and their major limitations 

The cyst size value for malignancy remains controversial. In the study reported by Sahora et al. ⁵, HGD was present in 6.5% of patients without malignancy criteria and a cyst size < 3 cm. Moreover, only a cyst size > 3 cm increased the possibility of IC up to 18%. Consequently, cyst size must be treated with caution and a close follow-up should be implemented. A rapid rate of cyst growth > 5 mm/2 years is included as a worrisome feature in the last review of Fukouka guidelines ².

Endoscopic ultrasonography with fine needle aspiration is currently a fundamental diagnostic method for the management of IPMN. Both an elevated serum level of carbohydrate antigen 19-9 and high grade epithelial atypia are included in the 2017 Fukuoka guidelines ².

Therefore, we want to highlight that although the different guidelines published for the diagnosis and management of this neoplasm are a starting point for the evaluation of our patients, we need to be careful when applying the different algorithms proposed in the international consensus guidelines.