Pancreatic intraductal papillary mucinous neoplasms: Current diagnosis and management

Table 1 Histological types and immunohistochemical profiles of intraductal papillary mucinous neoplasms[7,9]

Type	Percentage	Immunohistochemical profile
		MUC1	MUC2	MUC5AC	MUC6
Gastric	49-63	(-)	(-)	(+)	(+)
Intestinal	18-36	(-)	(+)	(+)	(±)
Pancreatobiliary	7-18	(+)	(-)	(+)	(±)
Oncocytis	1-8	(+)	(-)	(±)	(+)

MUC: Mucin.

Table 2 Indications for surgery in intraductal papillary mucinous neoplasms according to the International, European and American Gastroenterological Association guidelines[5,8,13,20-22,41]

Guidelines	Indications for surgery
IAP (2006)	Symptoms; Cyst size ≥ 3 cm; Mural nodule; MPD ≥ 5 mm; Positive cytology
AGA (2015)	High risk features: Cyst size ≥ 3 cm; Presence of solid component; Dilated MPD
	HGD or cancer on cytology
IAP (2017)	High risk stigmata: Jaundice; Enhancing mural nodule ≥ 5 mm; MPD ≥ 10 mm
	HGD or cancer on cytology
	Worrisome features: Cyst size ≥ 3 cm; Acute pancreatitis (due to IPMN)
	Enhancing mural nodule ≥ 5 mm; Thickened and enhancing cyst wall
	MPD dilation 5-9 mm; Abrupt change of MPD caliber with distal pancreatic atrophy; Presence of lymphadenopathy; Elevated serum CA 19-9; Cyst growth rate > 5 mm/2 yr
European (2018)	Absolute indications: Jaundice; Enhancing mural nodule ≥ 5 mm; MPD ≥ 10 mm; HGD or cancer on cytology; Solid mass
	Relative indications: Cyst size ≥ 4 cm; Enhancing mural nodule ≥ 5 mm/years; Acute pancreatitis (due to IPMN); New onset of diabetes; Rapidly increasing cyst size; Elevated serum levels of CA19-9

IPMN: Intraductal papillary mucinous neoplasm; IAP: International Association of Pancreatology; AGA: American Gastroenterological Association; MPD: Main pancreatic duct; HGD: High grade dysplasia.

Table 3 Management of intraductal papillary mucinous neoplasm patients regarding indications for surgery according to the International, European and American Gastroenterological Association guidelines[5,8,13,20-22,41]

Guidelines	Management
IAP (2006)	Indications: Surgery
AGA (2015)	Indications: Surgery
IAP (2017)	High risk stigmata: Surgery
	Worrisome features: Surgery versus close surveillance based on: Patients’ age/comorbidities: More aggressive management (surgery) in young patients
	EUS findings: Surgery indicated in clear MPD involvement and/or high-risk features
European (2018)	Absolute indications: Surgery
	Relative indications: Surgery according to criteria count, depending on comorbidities
	In fit patients: surgery for 1 criterion
	In patients with significant comorbidities: surgery for 2 criteria

IAP: International Association of Pancreatology; AGA: American Gastroenterological Association; EUS: Endoscopic ultrasonography; MPD: Main pancreatic duct.

Table 4 Surveillance in intraductal papillary mucinous neoplasm patients regarding indications for surgery according to the International, European and American Gastroenterological Association guidelines[5,8,13,20-22,41]

Guidelines	Indications	Investigations	Algorithm of follow-up
IAP (2006)	BD-IPMNs ≤ 30 mm; Without: Symptoms, mural nodules, positive cytology	MRI/MRCP or CT	Size ≤ 20 mm: every 6-12 mo; Size 20-30 mm: every 3-6 mo; The interval can be longer after 2 yr without changes
AGA (2015)	BD-IPMNs ≤ 30 mm; Without: Solid component, dilated MPD, HGD/cancer	MRI	Years 1, 2, 5 from initial diagnosis; It can be considered to discontinue; If there is no changes after years
IAP (2017)	No HRS/WF	MRI/MRCP, CT	Size < 10 mm: At 6 mo from diagnosis every 2 yr (if no change)
	No HRS/WF	MRI/MRCP, CT	Size 10-20 mm: At 6 mo from diagnosis yearly per 2 yr
	No HRS/WF	MRI/MRCP, EUS	Size 20-30 mm: EUS in 3-6 mo, yearly EUS or MRI
	No HRS, WF present and size < 30 mm	MRI/MRCPEUS	Every 3-6 mo EUS or MRI
European (2018)	No AI	MRI/MRCP or EUS, CA 19.9	Every 6 mo for the first year; Yearly after first year
	No AI, 1 RI in patient, with comorbidities	MRI/MRCP or EUS, CA 19.9	Every 6 mo

IPMN: Intraductal papillary mucinous neoplasm; IAP: International Association of Pancreatology; AGA: American Gastroenterological Association, MRI: Magnetic resonance imaging; MRCP: Magnetic resonance cholangiopancreatography; MPD: Main pancreatic duct; HGD: High grade dysplasia; EUS: Endoscopic ultrasonography; HRS: High risk stigmata; WF: Worrisome features; AI: Absolute indications for surgery; RI: Relative indications for surgery.