Observation or resection of pancreatic intraductal papillary mucinous neoplasm: An ongoing tug of war

Table 1 Comparison of existing guidelines for intraductal papillary mucinous neoplasia of the pancreas

Guideline (yr)	IAP (2017)	European (2018)	AGA (2015)	ACG (2018)
Resection criteria	≥ 1 high risk stigmata	≥ 1 absolute indication	Solid component and dilated MPD and/or concerning features on EUS-FNA	Decided by multidisciplinary team. Refer if ≥ 1 high risk characteristics
	≥ 1 worrisome feature and ≥ 1 of: definitive mural nodule ≥ 5 mm, MPD involvement, suspicious or positive cytology.	≥ 1 relative indication without significant co-morbidities
	Consider surgery in young fit patients with cysts > 2 cm	≥ 2 relative indications with significant co-morbidities
	MD-/MT IPMN if ≥ 1 high risk stigmata	MD-/MT IPMN
High risk features/surgery indications	High risk stigmata: Jaundice; Enhancing mural nodule > 5 mm; MPD > 10 mm	Absolute criteria: Jaundice; Enhancing mural nodule ≥ 5 mm; MPD ≥ 10 mm; Solid mass; Positive cytology	High risk features: Cyst size ≥ 3 cm; Dilated MPD; Solid component	High-risk characteristics: Jaundice; Mural nodule/solid component; MPD > 5 mm; Abrupt pancreatic duct calibre change with distal atrophy; Cyst size ≥ 3 mm; Cyst growth 3 mm/yr; Positive cytology; Pancreatitis secondary to cyst; Elevated serum Ca19-9
	Worrisome features: Pancreatitis secondary to cyst; Cyst size ≥ 3 cm; Enhancing mural nodule < 5 mm; Enhancing thickened cyst wall; MPD 5-9 mm; Abrupt pancreatic duct calibre change with distal atrophy; Growth ≥ 5 mm/2 yr; Elevated serum Ca19-9	Relative indications: Pancreatitis secondary to cyst; Cyst diameter ≥ 40 mm; Enhancing mural nodule < 5 mm; MPD 5-9 mm; Growth rate > 5 mm/yr; New onset diabetes mellitus; Elevated serum Ca19-9
Surveillance intervals	< 1 cm: 6 mo, then every 2 yr; 1-2 cm: 6 mo 1st yr, yearly for 2 yr, then every 2 yr; 2-3 cm: 3-6 mo 1st yr, then yearly; > 3 cm 3-6 mo	6 mo 1st yr, then yearly	1, 3 and 5 yr	< 1 cm: Every 2 yr; 1-2 cm: Every 1 yr; 2-3 cm: Every 6-12 mo; > 3 cm Every 6 mo and consider referral to MDT
Surveillance modality	< 2 cm MRI or CT; 2 cm MRI and EUS	MRI and/or EUS Serum Ca19-9	MRI	MRI and/or EUS

IAP: International Association of Pancreatology; AGA: American Gastroenterology Association; ACG: American College of Gastroenterology; MPD: Main pancreatic duct; MRI, Magnetic resonance imaging; EUS: Endoscopic ultrasound; FNA: Fine needle aspiration; IPMN: Intraductal papillary mucinous neoplasm; CT: Computed tomography; MDT: Multidisciplinary team; MD: Main duct; MT: Mixed type.