Abstract
BACKGROUND: Pancreatic neuroendocrine tumours (pNETs) are a highly heterogeneous group of tumours with widely variable biological behaviour. The incidence of pNETs has risen exponentially over the last three decades, particularly for asymptomatic small pNETs (≤2 cm), due to the widespread use of cross-sectional imaging in clinical practice. SUMMARY: Current consensus guidelines suggest that incidentally discovered pNETs ≤2 cm can be selectively followed due to the overall low risk of malignancy. Nevertheless, the "watch-and-wait" management strategy for small asymptomatic pNETs is still not widely accepted due to the lack of long-term data on the natural history of these small lesions. Additionally, it is clear that a subset of small pNETs may show malignant behaviour. KEY MESSAGE: Given the non-negligible risk of malignancy even in small pNETs, it is of the utmost importance to identify other preoperative factors, other than size, that may help to stratify the risk of malignant behaviour and guide clinical management. In this article, the Portuguese Pancreatic Club reviews the importance of risk stratification of pNETs and presents an updated perspective on the surveillance strategy for sporadic well-differentiated pNETs.