It depends on the type of cyst and location. IPMN’s when occurring in secondary and tertiary branch ducts are generally benign. Surgery may still be required if they grow to 3 cm as they can block those ducts leading to chronic pancreatitis and that can result in pancreatic cancer.

IPMN’s that occur in the main duct have a high tendency to turn malignant as well as when they are in a primary branch duct communicating to the main duct. Surgical resection is the course of action when they reach 1 cm in size.
https://pathology.jhu.edu/pancreas/ipmn
For those diagnosed with cysts, there is a clinical study recruiting for the purpose of determine the best surveillance method. It is being conducted at sites across the US. Information about the study-
https://ecog-acrin.org/clinical-trials/ea2185-pancreas-cancer-prevention/