S6 Serrated Epithelial Change: To Follow or Not to Follow?

Abstract

Case: Dysplasia surveillance is an important aspect of management in inflammatory bowel disease (IBD). A variety of lesions can be identified on surveillance biopsies, including serrated epithelial change (SEC). In this report, we aim to raise awareness about SEC and discuss its implications in IBD patients. Case 1: A 76 -year-old female with left sided ulcerative colitis (UC) on Adalimumab underwent a colonoscopy which revealed a flat 1 cm rectal polyp. Remainder of the colon was endoscopically normal and biopsies showed quiescent colitis, however polyp returned as SEC. Case 2: A 64 -year-old male with UC on Infliximab and a history of low grade dysplasia (LGD) on 2 previous surveillance colonoscopies presented for colonoscopy with chromoendoscopy. Previous area of dysplasia was biopsied and showed SEC with LGD. Remainder of colonic biopsies showed quiescent disease. Discussion: In accordance with established guidelines, patients with IBD are recommended to have regular colonoscopies every 1 to 2 years for dysplasia surveillance. Our patient in Case 2 had LGD for several years before SEC was seen, which raised the question of the importance of SEC and its dysplastic potential. While traditional serrated adenomas (TSA) and sessile serrated polyps are commonly seen in both IBD and non-IBD patients, SEC is a distinct entity that has only been described in patients with IBD. It has also been termed hyperplastic-like change and flat serrated change. There is no standardized endoscopic appearance of SEC. Histologically, SECs have crypt distortion and loss of perpendicular orientation of crypts with no typical features of dysplasia. Review of the current literature demonstrates differing opinions on the dysplasia risk associated with SEC. Brcic et al identified mutations in KRAS and BRAF genes in several serrated lesions, that were not seen in mucosa with SEC, implying that the neoplastic potential is comparatively lower in SEC. However, a separate study of serrated lesions identified evidence of aneuploidy that was present in TSA and SEC samples suggesting that there may be an association with neoplasia on a molecular level. From a clinical perspective, in 1 study of patients with SEC, 21% developed dysplasia over the observed 8-year period, suggesting a possible association between SEC and dysplasia, albeit not a causative one. A more recent case controlled study of 196 patients showed that in UC patients with SEC, the rate of metachronous/synchronous neoplasia was 26.5% compared with 3.1% in UC patients without SEC. High grade dyplasia was also seen more commonly in patients with UC and SEC (11.2%) compared with 2% in UC patients with SEC. This study concluded that due to this association, close attention should be paid on subsequent surveillance colonoscopies to patients with SEC. Conclusion: Ultimately, further controlled studies and prospective trials are needed to assess the true impact of SEC as a risk factor for dysplasia. This is still an under-recognized entity and the associations that have been noted in the recent studies suggest that closer endoscopic follow up may be necessary when SEC is revealed on surveillance biopsies.