Large-duct pattern invasive adenocarcinoma of the pancreas–a variant mimicking pancreatic cystic neoplasms: A minireview

Table 1 Patient characteristics of large-duct pancreatic ductal adenocarcinoma

Ref.	Number of cases	Median age	Sex		Tumor location
			Female	Male	Head	Body or tail
Kelly et al[34], 2012	10	67	6	4	9	1
Bagci et al[33], 2012	28	67	191	81	16	11
Kosmahl et al[35], 2005	24	58	15	9	122	92
Total	63	63.0	40	23	37	21

¹One case with missing information on sex.

²Three cases with missing information on tumor location.

Table 2 Clinical and morphological characteristics of pancreatic diseases

Ref.	Diseases	Median age	Sex (%, females)	Tumor location (%, pancreatic head)	Multifocality	Gross appearance	Cyst diameter	Main pancreatic duct communication	Internal structure	Other features	Key genetic alterations
Bagci et al[33], 2012	Large-duct PDA	63	68.3	56.2	No	Multiple small cysts	0.5–0.7 cm in each cyst	No	Dilatated glandular cyst (duct)	Dilatated glandular cyst (duct) is > 0.5 mm in diameter. Easily invades to the perineural plexus and shows desmoplastic reaction	KRAS (codon 12)
Kelly et al[34], 2012
Kosmahl et al[35], 2005
Youn et al[38], 2018
Seidel et al[18], 2002	Colloid carcinoma	61	52.9	66.7	Infrequent	Single or multiple cysts, well demarcated	1.2–16 cm	No	Well-defined pools of mucin, contained scanty malignant epithelial cells	Associated with intestinal-type IPMN	KRAS, BRAF, PIK3CA; MSIs are more frequently observed than non-colloid cancer PDA
Adsay et al[24], 2016
Tanaka et al[41], 2012	Branched duct-type IPMN	65–70	55.2	62.3	Yes	Bunch of grapes	Up to 30 mm for non-invasive IPMN; 30 mm or greater for IPMN with worrisome features	Yes	Cyst by cyst	Main pancreatic duct; normal or dilatated to > 5 mm, suggesting combined type with main duct IPMN	KRAS (codon 12), GNAS, RNF43
Kim and Cho[46], 2015
Laurent et al[51], 2016
Hecht et al[19], 2021	Main duct-type IPMN	60 s	41.3	59.6	Yes	Bunch of grapes	Up to 30 mm for non-invasive IPMN; 30 mm or greater for IPMN with worrisome features	Yes	Cyst by cyst	Main pancreatic duct; partial or diffuse dilatation > 5 mm	KRAS (codon 12), GNAS, RNF43, TP53
Tanaka et al[41], 2012
Salvia et al[50], 2010
Ånonsen et al[42], 2019	SCN	60–70	70	50	No	Spongy or honeycomb-like	3.7–5.1 cm	No	Microcystic or macrocystic		VHL
Wu et al[80], 2011
Ånonsen et al[42], 2019	MCN	40–50	95	5	Infrequent	Orange-like	1.0–26.4 cm	No	Cyst by cyst	Ovarian-like stroma	KRAS, RNF43
Yamao et al[43], 2011
Wu et al[80], 2011
Kim and Cho[46], 2015	Retention cyst	60 s	?	?	No	Unilocular	2.8–12 cm	Yes	No cellular dysplasia	Main pancreatic obstruction in should be observed downstream	?
Assifi et al[47], 2014
Singhi et al[61], 2012	Pancreatic neuroendocrine neoplasms with cystic changes	50 s	42	24	Infrequent, except MEN1-related neuroendocrine neoplasms	Pinkish-tan to yellowish in color, well demarcated	0.8–18.0 cm	No	Well circumscribed and surrounded by a thin-to-thick fibrous capsule	Larger cysts tend to show hemorrhage	MEN1, PTEN, DAXX, ATRX, MUTYH, CHEK2
Halfdanarson et al[62], 2008
Scarpa et al[86], 2017
Tanaka et al[41], 2012	Walled-off necrosis	40–50	25	45	Rare	Variable	Variable	Yes	Unilocular	Main pancreatic duct; normal or irregularly dilatated. Observed no later than 6 wk after the occurrence of acute pancreatitis
Cohen et al[45], 2003

PDA: Pancreatic ductal adenocarcinoma; IPMN: Intraductal papillary mucinous neoplasms; MCN: Mucinous cystic neoplasm; SCN: Solid cystic neoplasm.

Table 3 Mucin staining profiles of large-duct pancreatic ductal adenocarcinoma

Ref.	MUC1	MUC2	MUC5AC	MUC6
Kelly et al[34], 2012	10/10 (100.0%)	1/10 (90.0%)	9/10 (90.0%)	8/10 (80.0%)
Kosmahl et al[35], 2005	17/24 (70.8%)	2/24 (8.3%)	17/23 (73.1%)	12/23 (52.2%)
Total	27/37 (73.0%)	3/37 (8.1%)	26/36 (72.2%)	20/36 (55.6%)

No. of staining-positive cases/available cases. MUC: Mucin.