Pseudopolyps in inflammatory bowel diseases: Have we learned enough?

Table 1 Prevalence of pseudopolyps in inflammatory bowel disease

Ref.	Year of publication	IBD diagnosis	Prevalence of pseudopolyps	Special characteristics
Bargen et al[29]	1929	UC (n = 693)	10.0%
Baars et al[30]	2012	UC (n = 171)	30.0%	44% of UC patients and 30% of CD patients with unknown status for PP
		CD (n = 77)	38.0%
Baars et al[31]	2012	UC, CD (n = 152)	20.0%
Bacon et al[32]	1956	UC (n = 84)	57.1%	Colectomy specimens
Bockus et al[27]	1956	UC (n = 125)	74.0%	Hospitalized patients
Chang et al[21]	2007	CD (n = 23)	22.0%	Examined only small intestine
Chawla et al[26]	1990	UC (n = 50)	4.0%
Chuttani et al[33]	1967	UC (n = 46)	15.0%
De Dombal et al[17]	1966	UC (n = 465)	12.5%
De Felice et al[19]	2015	CD (n = 24)	4.0%	Location esophagus
Dukes et al[11]	1954	UC (n = 120)	10.0%	Colectomy specimens
Edwards et al[34]	1964	UC (n = 624)	14.9%
Geboes et al[39]	1975	CD (n = 43)	16.0%
Jalan et al[10]	1969	UC (n = 399)	18.7%
Kelly et al[6]	1987	UC, CD (n = 86)	UC: 36%	Colectomy specimens
			CD: 17%
			GPP: 4.6%
Lescut et al[35]	1993	CD (n = 20)	10.0%	Only small intestine examined as location
Luo et al[36]	2009	UC, CD (n = 34)	29.0%	Pediatric population
Maroo et al[37]	1974	UC (n = 122)	8.0%
Modigliani et al[50]	1990	CD (n = 142)	41.0%	Active colonic or ileocolonic CD
Ray et al[38]	2011	UC (n = 40)	27.0%
Rutter et al[44]	2004	UC (n = 136)	39.0%	Control population without CRC Population with CRC
Tandon et al[40]	1965	UC (n = 69)	17.6%
Teague et al[41]	1975	UC (n = 150)	17.0%
Teh et al[42]	1987	UC (n = 61)	21.3%
Velayos et al[43]	2006	UC (n = 188)	42.0%	Control population without CRC Population with CRC
		UC (n = 188)	56.0%
Wang et al[45]	2007	UC (n = 2726)	22.0%	Active UC
Watts et al[46]	1966	UC (n = 169)	47.0%	Surgical specimens
Waugh et al[47]	1964	UC (n = 205)	5.9%	Surgical specimens
Wright et al[48]	1965	UC (n = 269)	10.0%
Zheng et al[49]	2007	CD (n = 27)	48.0%

CD: Crohn's disease; CRC: Colorectal cancer; IBD: Inflammatory bowel disease; UC: Ulcerative colitis.

Table 2 Pseudopolyps and increased incidence of colorectal cancer

Ref.	Year of publication	IBD diagnosis	Format of study	Cancer risk
Rutter et al[44]	2004	UC with CRC (n = 68)	Case-control study 1:2, documentation of PP	OR = 2.29; 95%CI: 1.28-4.11
Velayos et al[43]	2006	UC with CRC (n = 188)	Case-control study 1:1, history of PP	OR = 2.5; 95%CI: 1.4-4.6
Baars et al[57]	2011	UC (n = 113)	Case-control study 1:2	RR = 1.92; 95%CI: 1.28 -2.88
		CD (n = 58)
		IC (n = 2)

CD: Crohn's disease; CRC: Colorectal cancer; IBD: Inflammatory bowel disease; IC: Intermediate colitis; OR: Odds ratio; PP: Pseudopolyp; RR: Relative risk; UC: Ulcerative colitis.

Table 3 Characteristics for differential diagnosis between pseudopolyps, adenoma-like DALM and non-adenoma-like DALM

	Pseudopolyps	Adenoma-like DALM	Non-adenoma-like DALM
Number	Often multiple	Can be multiple, usually solitary	Usually solitary
Location	Located in area inside colitis	Located in area inside and outside colitis	Located in area inside colitis
Endoscopic appearance	Smooth surface, can have exudate, definite borders, pale surface	Well circumscribed, definite borders, smooth surface sessile or pedunculated	Not amenable to endoscopic removal, irregular borders, often ulcerated or necrotic material
Management	No necessity for removal or biopsies except doubt	Endoscopic removal and endoscopic surveillance if dysplasia not recognized in adjacent mucosa or in other area of colitis	Proctocolectomy when HDG in lesion or multifocal LGD in area of colitis

DALM: Dysplasia-associated lesion or mass; HGD: High-grade dysplasia; LGD: Low-grade dysplasia.

Table 4 Summary of characteristics of pseudopolyps and other polypoid lesions in inflammatory bowel disease

Pseudopolyps and polypoid manifestation	Characterization
Location	Upper gastrointestinal tract
	Small bowel
	Large bowel
	Both small and large intestine
	Special location (pouch)
Size	< 1.5 cm
	> 1.5 (giant)
Number	< 10
	> 10 multiple
Pattern of distribution	Congested
	Scarce
Years since disease onset	< 1 yr
	1-5 yr
	> 5 yr
Bowel background mucosa	Relapsed
	Remission
Endoscopic appearance	Obstructing
	Bridging (mural bridging lesions)
	Penduculated
	Filiform (digitiform or fingerlike)
	Flat
	Mixed type (> 2 types of previous categories)
	Long, glistering, with or without exudate
	Resectable or not
	Definite borders, not stricturing
Histology	Inflammatory
	Adenomatous
	Dysplastic low-grade (DALM)
	Dysplastic high-grade (DALM)
	Serrated
IBD type	Ulcerative colitis
	Crohn's disease
	Indeterminate colitis
Follow-up	Reduction in number
	Reduction in size
	Increase in number
	Increase in size

DALM: Dysplasia-associated lesion or mass; IBD: Inflammatory bowel disease.