When to operate pancreatic intraductal papillary mucinous neoplasm: Literature review

Table 3 It summarizes the indications of surgery and surveillance/follow-up for intraductal papillary mucinous neoplasms

Items	IAP (2006)	American Gastroenterological Association (2015)	IAP (2017)
Indications for surgery	Size of the cyst is ≥ 3 cm. Mural nodule. Dilatation of MPD ≥ 5 mm. Positive fine needle aspiration cytology	High risk features: The size of cyst is ≥ 3 cm; solid part; dilated MPD. High-grade dysplasia or cancer on cytology	HRS include: Sign (jaundice); nodules enhancement ≥ 5 mm; MPD ≥ 10 mm. High-grade dysplasia or cancer on cytology WF: Cyst size is ≥ 3 cm; acute pancreatitis as a complication of IPMN. Thickened and enhancing cyst wall. Dilated MPD caliber 5-9 mm is associated with abrupt change of with distal pancreatic atrophy. Presence of lymphadenopathy. Elevated serum carbohydrate antigen 19-9. Cyst growth rate > 5 mm/2 years
Surveillance and follow-up	BD-IPMNs ≤ 30 mm without symptoms, or mural nodules, or positive cytology. MRI/MRCP or CT. Size ≤ 20 mm: Follow-up every 6-12 months. Size 20-30 mm: Follow-up every 3-6 months. The intermission can be prolonged if there are no changes after 2 years	BD-IPMNs ≤ 30 mm without solid component, or dilated MPD, or high-grade dysplasia/cancer. MRI. Years 1, 2, 5 from initial diagnosis; it can be considered to discontinue, if there are no changes after year	No HRS/WF: MRI/MRCP, CT size < 10 mm: The follow-up at 6 months from diagnosis every 2 years (if no change). No HRS/WF: MRI/MRCP, CT size 10-20 mm: The follow-up at 6 months from diagnosis yearly per 2 years. No HRS/WF: MRI/MRCP, EUS, size 20-30 mm, do EUS in 3-6 months, yearly EUS or MRI. No HRS, WF present: Size < 30 mm, MRI/MRCP EUS, every 3-6 months: EUS or MRI

BD-IPMNs: Branch-duct intraductal papillary mucinous neoplasms; CT: Computerized tomography; EUS: Endoscopic ultrasound; HRS: High-risk stigmata; IAP: International Association of Pancreatology; IPMNs: Intraductal papillary mucinous neoplasms; MPD: Main pancreatic duct; MRCP: Magnetic resonance cholangiopancreatography; MRI: Magnetic resonance imaging; WF: Worrisome feature.