Introduction
In Inflammatory Bowel Disease (IBD), histological assessment of colonic biopsies may detect areas “indefinite for dysplasia” (IND). This definition is used when a definite distinction between non-neoplastic changes and neoplasia is not possible(1). The role of this finding in predicting the endoscopic and histological findings in IBD colitis is currently undefined.
Aims & Methods
Primary aim was to evaluate the outcome of IBD patients(pts) with an initial histological finding of areas IND in random colonic biopsies, followed up for ≥ 3 years. At this purpose, all IBD pts showing areas IND in colonic biopsies taken from March 2018 to March 2022, subsequently followed up for ≥3 years including ≥ 1 control colonoscopy were retrospectively enrolled. All pts were in regular follow up at our referral IBD Unit and underwent colonoscopy with histological assessment in the same center.
Results
The study population included 99 pts with IBD colitis and histological aspects IND detected in random colonic biopsies in 79(79.8%) pts and in target biopsies in 20(20.2%) pts. In the 79 pts, areas IND were detected in random biopsies taken from: rectum in 62(78%), left colon in 29(36%), transverse colon in 6(7.5%), right colon in 5(6.3%), >1 area in 18(22.3%) pts. In the 20 pts with areas IND on target biopsies, these were taken from stenosis (5 pts), polyps (9 pts), lateral spreading tumors (2 pts), flat elevated mucosa (4 pts). For the aim of the study, only the 79 IBD pts (37 females, 46.8%) showing in random colonic biopsies areas IND were considered. These 79 IBD pts (69 UC, 9 CD, 1 unclassified colitis) showed median age of 51 [18-79], long-standing IBD in 54(68.4%), family history of CRC in 11(13.9%), concomitant primary sclerosing cholangitis in 1(1.3%) pt. Random biopsies were taken from colonic mucosa proximal to ulcerations in 54(68.4%) pts, erosions in 19(24%) pts and to mild inflammation in 6(7.6%) pts. The second colonoscopy was performed after a median of 11[1-42] months. In the 79 pts with a first evidence of areas IND on random biopsies, the second colonoscopy detected: dysplasia in 10(12.6%) pts (high grade, HGD in 2[2.5%], low grade dysplasia, LGD in 8[10.1%]pts), areas IND in 12(15.2%) pts, no dysplasia (HGD, LGD or IND) in 38(48.1%) pts, while in the remaining 16(20.3%) pts no reliable histology was available. LGD at second colonoscopy was detected in random biopsies (4pts) or in target biopsies (4pts). Differently, in both pts with HGD it was detected in target biopsies, including one focal area of adenocarcinoma (CRC) in 1(1.3%) pt. Areas IND confirmed at second colonoscopy were detected in the same colonic segment in 11(13.9%) pts and in a different segment in 1(1.3%) pt. After the second colonoscopy, 4 out of the 79 IBD pts required IBD-related colonic surgery, and histology of the surgical specimen detected LGD in 1 pt, CRC in 1 pt and areas IND in 2 pts. During the study period (median 27[2-75] months) 51 out of the 79(64.5%) IBD pts repeated a third colonoscopy detecting: areas IND in 4(7.8%), LGD in 6(11.8%), HGD in 1(2%) pts and no CRC.
| IND | LGD | HGD | CRC |
| 1st Colonoscopy (n=79), n (%) | 79 (100%) | 0 (0%) | 0 (0%)
| 0 (0%)
|
| 2nd Colonoscopy (n=79), n (%) | 12 (15.2%) | 8 (10.1%) | 2 (2.5%) | 1 (1.3%) |
| 3rd Colonoscopy (n=51), n (%) | 4 (7.8%) | 6 (11.8%)
| 1 (2%)
| 0 (0%) |
Table1 Indefinite for dysplasia (IND) in IBD colitis: outcome at 3 years
Conclusion
Patients with IBD colitis showing areas indefinite for dysplasia deserve careful endoscopic surveillance as dysplasia and CRC may be detected at subsequent colonoscopies.
References
1. Feakins R, Borralho Nunes P, Driessen A, Gordon IO, Zidar N, Baldin P, Christensen B, Danese S, Herlihy N, Iacucci M, Loughrey MB, Magro F, Mookhoek A, Svrcek M, Rosini F. Definitions of Histological Abnormalities in Inflammatory Bowel Disease: an ECCO Position Paper. J Crohns Colitis. 2024 Feb 26;18(2):175-191.