Influence of SCENIC recommendations on terminology used for histopathologic diagnosis of inflammatory bowel disease-associated dysplasia

Table 1 Histopathologic diagnoses of polyps and polypoid lesions detected during surveillance colonoscopies in ulcerative colitis patients during pre-SCENIC (2012-2014) and post-SCENIC (2016-2018) periods

Histopathologic diagnosis	Pre-SCENIC (n = 347)	Post-SCENIC (n = 419)
Adenocarcinoma	3	3
TA	32	80
TVA	2	17
VA	0	2
Adenoma with HGD	2	2
LGD	14	1
LGD with focal HGD	0	1
HGD	2	1
Polypoid LGD	1	0
LGD with tubulovillous features	2	0
Adenomatous change/LGD	2	0
Adenomatous change with focal HGD	1	0
DALM	1	0
Combined serrated and low-grade adenomatous features	1	0
IND	14	6
HP	55	63
SSA/P	9	22
TSA	0	1
Hyperplastic change	51	81
Serrated epithelial change	1	0
Inflammatory polyp/pseudopolyp	143	96
Benign lymphoid aggregate	5	17
Well-differentiated NET	0	1
Pneumatosis intestinalis	0	1
Mucosal prolapse	0	2
Collagenous colitis	0	1
Submucosal giant cells	1	0
Atypical epithelial proliferation	0	1
Polypoid normal mucosa	4	20
Branching crypts	1	0

SCENIC: Surveillance for Colorectal Endoscopic Neoplasia Detection and Management in Inflammatory Bowel Disease Patients; UC: Ulcerative colitis; TA: Tubular adenoma; TVA: Tubulovillous adenoma; VA: Villous adenoma; LGD: Low-grade dysplasia; HGD: High-grade dysplasia; DALM: Dysplasia-associated lesion or mass; IND: Indefinite for dysplasia; HP: Hyperplastic polyp; SSA/P: Sessile serrated adenoma/polyp; TSA: Traditional serrated adenoma; NET: Neuroendocrine tumor.

Table 2 Comparison of comments on histopathologic diagnoses of polypoid adenomatous/dysplastic lesions detected in ulcerative colitis patients during surveillance colonoscopies between pre-SCENIC (2012-2014) and post-SCENIC (2016-2018) periods

Histopathologic diagnosis	No. of cases (%)	Comment
		No. of cases	Favor sporadic adenoma	Favor DALM	Cannot distinguish
Pre-SCENIC
TA	32 (53.3)	6	5		1
TVA	2 (3.3)	0
TA with focal HGD	2 (3.3)	0
Adenomatous change/LGD	2 (3.3)	2		1	1
Adenomatous change with focal HGD	1 (1.7)	1		1
LGD	14 (23.3)	10	4	1	5
Polypoid LGD	1 (1.7)	1			1
LGD with tubulovillous features	2 (3.3)	2		1	1
HGD	2 (3.3)	0
DALM	1 (1.7)	1		1
Combined serrated and low-grade adenomatous features	1 (1.7)	0
Total	60 (100)	23	9	5	9
Post-SCENIC
TA	80 (76.9)	4	4
TVA	17 (16.3)	0
TVA with focal HGD	2 (1.9)	0
VA	2 (1.9)	0
LGD	1 (1.0)	1			1
LGD with focal HGD	1 (1.0)	1			1
HGD	1 (1.0)	0
Total	104 (100)	6	4	0	2

SCENIC: Surveillance for Colorectal Endoscopic Neoplasia Detection and Management in Inflammatory Bowel Disease Patients; UC: Ulcerative colitis; DALM: Dysplasia-associated lesion or mass; TA: Tubular adenoma; TVA: Tubulovillous adenoma; VA: Villous adenoma; LGD: Low-grade dysplasia; HGD: High-grade dysplasia.

Table 3 Histopathologic diagnoses of dysplastic lesions on random endoscopic biopsies from ulcerative colitis patients during pre-SCENIC (2012-2014) and post-SCENIC (2016-2018) periods

Histopathologic diagnosis	No. of cases	Multiple or extensive	Comment
			No. of cases	Favor sporadic adenoma	Favor IBD dysplasia	Cannot distinguish
Pre-SCENIC
LGD	13	5	3		2	1
LGD, villous type	1	1	1			1
Low-grade adenomatous change	1	0	1	1
Low-grade villous dysplasia	1	1	0
HGD	1	1	0
Total	17	8	5
Post-SCENIC
LGD	12	7	3		21	12
LGD/TA	2	1	0
HGD	2	1	0
Total	16	9	3

¹Diagnosed in 2016 and 2017.

²Diagnosed in 2016.

SCENIC: Surveillance for Colorectal Endoscopic Neoplasia Detection and Management in Inflammatory Bowel Disease Patients; UC: Ulcerative colitis; IBD: Inflammatory bowel disease; LGD: Low-grade dysplasia; HGD: High-grade dysplasia; TA: Tubular adenoma.

Table 4 Comparison of Sessile serrated adenoma/polyp diagnosed in ulcerative colitis patients between pre-SCENIC (2012-2014) and post-SCENIC (2016-2018) periods

		Pre-SCENIC		Post-SCENIC
		No.	%	No.	%
No. of biopsies/patients		9/9		22/17
Frequency		9/1203	0.7	22/1273	1.7
Diagnosis	SSA/P	31	33.3	211	95.5
	SSA	5	55.6	1	4.5
	SSP	1	11.1	0
Single		9	100	17	77.3
Multiple		0		5	22.7
	Right	4	44.4	9	41
	Transverse	1	11.1	5	22.7
Location	Left	3	33.3	4	18.2
	Rectum	1	11.1	2	9.1
	Multiple sites	0		2	9.1
Synchronous adenoma		42	44.4	43	21.1
No. of patients with follow-up
	Biopsy	5		6
	Resection	24		0
Metachronous adenoma		45	44.4	36	15.8

¹One case with low-grade cytologic dysplasia.

²Tubular adenoma (TA) = 2, TA with focal high-grade dysplasia = 1, indefinite for dysplasia = 1.

³TA = 4.

⁴One case had history of pseudopolyps, dysplasia, and sigmoid stricture. The other case had synchronous multiple TAs/low-grade dysplasia (LGD).

⁵TA/LGD = 3, dysplasia (grade not provided) = 1.

⁶TA = 2, TA and sessile serrated adenoma/polyp = 1.

SCENIC: Surveillance for Colorectal Endoscopic Neoplasia Detection and Management in Inflammatory Bowel Disease Patients; SSA: Sessile serrated adenoma; SSP: Sessile serrated polyp; SSA/P: Sessile serrated adenoma/polyp.

Table 5 Comparison of serrated epithelial change diagnosed on random endoscopic biopsies from ulcerative colitis patients between pre-SCENIC (2012-2014) and post-SCENIC (2016-2018) periods

		Pre-SCENIC		Post-SCENIC
		Hyperplastic change (%)	SEC	Hyperplastic change (%)	SEC	SSA/P
Total		47	2	61	3	2
Location	Right	2 (4.3)	0	5 (8.2)	0	1
	Transverse	2 (4.3)	0	3 (4.9)	0	1
	Left	17 (36.2)	2	14 (23.0)	1	0
	Rectum	16 (34.0)	0	31 (50.8)	0	0
	Multiple sites	10 (21.3)	0	8 (13.1)	2	0
Synchronous adenoma/dysplasia
	TA	41 (8.5)	11	5 (8.2)	0	0
	LGD	42 (8.5)	0	2 (3.3)	0	0
	SSA/P	0	0	1 (1.6)	1	0
No. of cases with follow-up biopsies		33	2	31	3	1
Metachronous dysplasia
	TVA	11 (3.0)	0	1 (3.2)	0	0
	TA	1 (3.0)	1	61 (19.4)	0	0
	LGD	3 (9.1)	0	2 (6.5)	0	0
	SSA/P	1 (3.0)	0	1 (3.2)	0	0
	IND	0	0	1 (3.2)	0	0

¹One case had multiple adenomas.

²Two cases had multiple foci of LGD.

SCENIC: Surveillance for Colorectal Endoscopic Neoplasia Detection and Management in Inflammatory Bowel Disease Patients; SEC: Serrated epithelial change; SSA/P: Sessile serrated adenoma/polyp; TA: Tubular adenoma; TVA: Tubulovillous adenoma; LGD: Low-grade dysplasia; IND: Indefinite for dysplasia.

Table 6 Indications for total colectomies and postoperative findings for ulcerative colitis patients during pre-SCENIC (2012-2014) and post-SCENIC (2016-2018) periods

	No. of cases (%)	Preoperative biopsy/polypectomy (No. of cases)	Postoperative findings (No. of cases)
Pre-SCENIC
Total	54
Refractory UC	34 (63.0)	No dysplasia/adenoma or malignancy (34)	Incidental well-differentiated (low-grade) NET (1); TA (1); no dysplasia/adenoma or malignancy (32)
Complications	6 (11.1)	Perforation (2); fistula (1); stricture (1); volvulus (1); obstruction (1)1	No dysplasia/adenoma or malignancy (6)
Dysplasia/malignancy	14 (25.9)	Invasive adenocarcinoma (4.5 cm mass lesion), a separate focus of LGD	pT4a pN2b adenocarcinoma, a separate focus of HGD
		Invasive adenocarcinoma (6.3 cm mass), a separate focus of LGD	pT3 pN0 adenocarcinoma
		At least HGD (2.6 cm polypoid lesion)	pT1 pN1a adenocarcinoma (2 foci)
		At least HGD (2.0 cm polypoid lesion)	pT1 pN1a adenocarcinoma (2 foci), separate foci of HGD
		Dysplasia (3.6 cm mass)	pT2 pN1b mucinous adenocarcinoma
		HGD (3.0 cm polypoid lesion), also separate foci of LGD	HGD
		Multiple TAs and foci of LGD, one TA with HGD, one SSA/P with low-grade cytologic dysplasia (0.2-1.5 cm sessile polyps)	Multiple TAs and foci of LGD
		LGD (1.0 cm lesion)	pT1 pN0 mucinous adenocarcinoma arising from extensive LGD
		LGD with tubulovillous features (6.5 cm mucosal plaque)	LGD
		LGD (4.6 cm polypoid lesion)	LGD
		Dysplasia (outside diagnosis)	LGD
		LGD (focal on a random biopsy)	No residual dysplasia or carcinoma
		Extensive LGD	Extensive LGD
		Multiple foci of LGD	Focal LGD
Post-SCENIC
Total	40
Refractory UC	26 (65.0)	No dysplasia/adenoma or malignancy (26)	Focal LGD (1); no dysplasia/adenoma or malignancy (25)
Complications	2 (5.0)	Perforation (1); GI bleeding (1)2	Extensive HGD (1)2; no dysplasia/adenoma or malignancy (1)
Dysplasia/malignancy	12 (30.0)	Invasive adenocarcinoma (4.1 cm mass)	pT4a pN1a poorly differentiated NEC
		Invasive adenocarcinoma (1.5 cm mass)	pT3 pN1a adenocarcinoma, separate foci of LGD
		Invasive adenocarcinoma (5.5 polypoid mass), a separate focus of LGD	pT3 pN1a poorly differentiated NEC
		Invasive adenocarcinoma with mucinous features arising in a polypoid lesion with serrated/villiform dysplasia (1.5 cm polyp)	No residual carcinoma or dysplasia
		Invasive adenocarcinoma (2.8 cm mass)	No residual carcinoma or dysplasia (s/p neoadjuvant chemotherapy)
		Atypical cells concerning for adenocarcinoma (13.0 cm mass)	pT4b pN0 mucinous adenocarcinoma
		At least HGD (2.5 cm mass)	pT1 pN0 adenocarcinoma with signet-ring cell features (3 foci)
		Extensive HGD (3.5 cm flat induration)	pT2 pN0 adenocarcinoma (3 foci)
		TVA with focal HGD (6.1 cm mass)	pT2 pN0 adenocarcinoma
		Villous adenoma (2.0 cm sessile polyp)	No residual adenoma or carcinoma
		Multifocal LGD, one TA	Focal LGD and HGD
		LGD with tubulovillous architecture (12 cm polypoid lesion), a separate focus of LGD, multiple TVAs	Villous adenoma

¹Surveillance colonoscopy found a small polypoid area in the sigmoid colon that caused partial obstruction. Biopsy showed features of sessile serrated adenoma/polyp without cytologic dysplasia. No dysplasia or carcinoma was found on resection specimen.

²Surveillance biopsy showed indefinite for dysplasia, resection specimen identified extensive high-grade dysplasia.

SCENIC: Surveillance for Colorectal Endoscopic Neoplasia Detection and Management in Inflammatory Bowel Disease Patients; UC: Ulcerative colitis; SSA/P: Sessile serrated adenoma/polyp; NET: Neuroendocrine tumor; TA: Tubular adenoma; TVA: Tubulovillous adenoma; LGD: Low-grade dysplasia; HGD: High-grade dysplasia; IND: Indefinite for dysplasia; NEC: Neuroendocrine carcinoma.