Clinicopathologic Features of Undetected Dysplasia Found in Total Colectomy or Proctocolectomy Specimens of Patients with Inflammatory Bowel Disease

Dysplasia Detected in Patients With Serrated Epithelial Change Is Frequently Associated With an Invisible or Flat Endoscopic Appearance, Nonconventional Dysplastic Features, and Advanced Neoplasia

The significance of serrated epithelial change (SEC), defined as endoscopically invisible hyperplastic polyp (HP)-like mucosal change identified in patients with inflammatory bowel disease (IBD), remains unclear. Although some studies reported an increased risk of synchronous and/or metachronous colorectal neoplasia in patients with SEC, including advanced neoplasia (high-grade dysplasia or colorectal cancer), the development of SEC is not significantly associated with increased colonic inflammation. This contrasts with the reported positive correlation between increased colonic inflammation and the risk of colorectal neoplasia in ulcerative colitis, arguing against the notion that SEC may represent a form of dysplasia. As such, this study aimed to characterize the features of synchronous and metachronous dysplasia detected in patients with SEC to identify factors contributing to the increased risk of colorectal neoplasia, including advanced neoplasia, observed in a subset of these patients. Clinicopathologic features of 46 IBD patients with SEC (n=109) and synchronous and/or metachronous dysplasia (n=153) were analyzed. All dysplastic lesions were subtyped as either conventional or nonconventional dysplasia. As controls, 45 IBD patients with endoscopically visible or polypoid HP (n=75) and synchronous and/or metachronous dysplasia (n=87) were analyzed. The SEC group included 28 (61%) men and 18 (39%) women with a mean age of 58 years and a long history of IBD (mean duration: 23 years). The majority of patients (n=34; 74%) had ulcerative colitis, and 12 (26%) had Crohn's disease. Thirty-nine (85%) patients had a history of pancolitis, and 2 (4%) had concomitant primary sclerosing cholangitis. Twenty-seven (59%) patients had multifocal SEC. SEC was predominantly found in the left colon (n=52; 48%) and rectum (n=34; 31%). Dysplasia in the SEC group was often endoscopically invisible or flat (n=42; 27%) and demonstrated nonconventional dysplastic features (n=49; 32%). Six nonconventional subtypes were identified in the SEC group, including 17 (11%) dysplasia with increased Paneth cell differentiation, 12 (8%) hypermucinous dysplasia, 8 (5%) crypt cell dysplasia, 7 (5%) goblet cell deficient dysplasia, 3 (2%) sessile serrated lesion-like dysplasia, and 2 (1%) traditional serrated adenoma-like dysplasia. Advanced neoplasia was detected in 11 (24%) patients. The SEC group was more likely to have nonconventional dysplasia (32%, P<0.001), invisible/flat dysplasia (27%, P<0.001), and advanced neoplasia (24%, P<0.001) than the control group (7%, 2%, and 0%, respectively). High-risk nonconventional subtypes (ie, hypermucinous, crypt cell, and goblet cell deficient dysplasias) accounted for 18% of all dysplastic lesions in the SEC group, which were not seen in the control group (P<0.001). The SEC group (n=35; 76%) also had a higher rate of concordance between the location of SEC and the area of synchronous/metachronous dysplasia than the control group (n=22; 49%) (P=0.007). In conclusion, dysplasia detected in patients with SEC is often endoscopically invisible/flat (27%), nonconventional (32%, including the high-risk subtypes), and found in the same colonic segment as SEC (76%), which may in part explain why some patients with SEC are associated with an increased risk of colorectal neoplasia, including advanced neoplasia. The finding of SEC may warrant a careful follow-up colonoscopy with increased random biopsy sampling, especially in the segment of colon with SEC.

Nonconventional Dysplasia is Frequently Associated With Goblet Cell Deficient and Serrated Variants of Colonic Adenocarcinoma in Inflammatory Bowel Disease

Various subtypes of nonconventional dysplasia have been recently described in inflammatory bowel disease (IBD). We hypothesized that goblet cell deficient dysplasia and serrated dysplasia may be the primary precursor lesions for goblet cell deficient (GCDAC) and serrated (SAC) variants of colonic adenocarcinoma, respectively. Clinicopathologic features of 23 GCDAC and 10 SAC colectomy cases were analyzed. All dysplastic lesions found adjacent to the colorectal cancers (n = 22 for GCDACs and n = 10 for SACs) were subtyped as conventional, nonconventional, or mixed-type dysplasia. As controls, 12 IBD colectomy cases with well to moderately differentiated adenocarcinoma that lacked any mucinous, signet ring cell, low-grade tubuloglandular, or serrated features while retaining goblet cells throughout the tumor (at least 50% of the tumor) were evaluated. The cohort consisted of 19 (58%) men and 14 (42%) women, with a mean age of 53 years and a long history of IBD (mean duration: 18 y). Twenty-seven (82%) patients had ulcerative colitis. GCDACs (57%) were more often flat or invisible than SACs (10%) and controls (25%; P = 0.023). The GCDAC and SAC groups were more likely to show lymphovascular invasion (GCDAC group: 52%, SAC group: 50%, control group: 0%, P = 0.001) and lymph node metastasis (GCDAC group: 39%, SAC group: 50%, control group: 0%, P = 0.009) than the control group. Notably, GCDACs and SACs were more frequently associated with nonconventional dysplasia than controls (GCDAC group: 77%, SAC group: 40%, control group: 0%, P < 0.001). Goblet cell deficient dysplasia (73%) was the most prevalent dysplastic subtype associated with GCDACs ( P = 0.049), whereas dysplasias featuring a serrated component (60%) were most often associated with SACs ( P = 0.001). The GCDAC group (75%) had a higher rate of macroscopically flat or invisible synchronous dysplasia compared with the SAC (20%) and control (33%) groups ( P = 0.045). Synchronous dysplasia demonstrated nonconventional dysplastic features more frequently in the GCDAC (69%) and SAC (40%) groups compared with the control group (0%; P = 0.016). In conclusion, goblet cell deficient dysplasia and dysplasias featuring a serrated component could potentially serve as high-risk markers for GCDACs and SACs, respectively.

Histopathological Evaluation of Pouch Neoplasia in IBD and Familial Adenomatous Polyposis

BACKGROUND

IPAA is often required for patients with ulcerative colitis or familial adenomatous polyposis after colectomy. This procedure reduces but does not completely eliminate the risk of neoplasia.

OBJECTIVE

This study focuses on the histopathology of neoplasia in the ileal pouch, rectal cuff, and anal transition zone.

DATA SOURCES

We performed a MEDLINE search for English-language studies published between 1981 and 2022 using the PubMed search engine. The terms "ileal pouch-anal anastomosis," "pouchitis," "pouch dysplasia," "pouch lymphoma," "pouch squamous cell carcinoma," "pouch adenocarcinoma," "pouch neoplasia," "dysplasia of rectal cuff," and "colitis-associated dysplasia" were used.

STUDY SELECTION

Human studies of neoplasia occurring in the pouch and para-pouch were selected, and the full text was reviewed. Comparisons were made within and across studies, with key concepts selected for inclusion in this article.

CONCLUSIONS

Neoplasia in the pouch is a rare complication in patients with IPAA. Annual endoscopic surveillance is recommended for familial adenomatous polyposis patients and ulcerative colitis patients with a history of prior dysplasia or carcinoma. In familial adenomatous polyposis, dysplastic polyps of the pouch are visible and readily amenable to endoscopic removal; however, glandular dysplasia in the setting of ulcerative colitis may be invisible on endoscopy. Therefore, random biopsies and adequate tissue sampling of the pouch and rectal cuff are recommended in this setting. The histological diagnosis of IBD-associated dysplasia can be challenging and should be confirmed by at least 1 expert GI pathologist. See video from the symposium.

Increased Active Inflammation in the Colon is Not a Reliable Predictor of an Elevated Risk of Dysplasia in Patients With Primary Sclerosing Cholangitis and Ulcerative Colitis

Although the increased risk of colorectal neoplasia in patients with both primary sclerosing cholangitis (PSC) and ulcerative colitis (UC; termed PSC-UC) is well documented, the mechanism through which concomitant PSC increases the risk of colorectal neoplasia remains unclear. Given that the risk of colorectal neoplasia in UC is positively correlated with increased histologic inflammation, this study sought to investigate whether increased histologic inflammation could be used to stratify the risk of dysplasia development in patients with PSC-UC. Twenty patients with PSC-UC and dysplasia were compared with 30 control patients with PSC-UC who had no history of neoplasia. For each patient, all surveillance biopsies were scored using a 4-point scoring system: (1) no epithelial neutrophils = 0, (2) cryptitis only = 1, (3) cryptitis plus crypt abscess in <50% of crypts = 2, and (4) crypt abscess in ≥50% of crypts, erosion, neutrophilic exudate, and/or ulceration = 3. A score was designated for each biopsy, and both mean and maximum inflammation scores were calculated from all biopsies taken during each colonoscopy. The inflammation burden score was calculated for each surveillance interval by multiplying the average maximum score between each pair of surveillance episodes by the length of the surveillance interval in years. The average scores derived from all colonoscopies for each patient were used to determine the patient's overall mean, maximum, and inflammation burden scores. In both the dysplasia and control groups, the 3 summative inflammation scores were calculated independently for the entire colon, right colon, and left colon. The dysplasia group consisted of 14 (70%) men and 6 (30%) women, with a mean age of 27 years at UC diagnosis and a long history of pancolitis (mean duration: 17 y). A total of 49 dysplastic lesions were detected in the dysplasia group, and 8 (40%) of the 20 patients had multifocal dysplasia. The majority of dysplastic lesions belonged to nonconventional subtypes (n = 28; 57%) and were located in the right colon (n = 37; 76%). Irrespective of the colon segment, there was no significant difference in the 3 summative inflammation scores between the dysplasia and control groups (P > 0.05). However, in each group, the 3 summative inflammation scores were significantly higher in the right colon than in the left colon (P< 0.05). In conclusion, patients with PSC-UC exhibit increased histologic inflammation in the right colon compared with the left colon, regardless of the presence of dysplasia. Although this may provide an explanation for the predominance of right-sided colorectal neoplasia in patients with PSC-UC, increased histologic inflammation does not reliably predict an elevated risk of dysplasia in patients with PSC-UC. These findings reinforce the current recommendation for annual endoscopic surveillance for all patients with PSC-UC, irrespective of the extent and severity of inflammation.

Pathology and Clinical Significance of Inflammatory Bowel Disease-Associated Colorectal Dysplastic Lesions

Timely diagnosis and effective management of colorectal dysplasia play a vital role in preventing mortality from colorectal cancer in patients with chronic inflammatory bowel disease. This review provides a contemporary overview of the pathologic and endoscopic classification of dysplasia in inflammatory bowel disease, their roles in determining surveillance and management algorithms, and emerging diagnostic and therapeutic approaches that might further enhance patient management.

Gastric metaplasia as a precursor of nonconventional dysplasia in inflammatory bowel disease

Gastric metaplasia in colonic mucosa with inflammatory bowel disease (IBD) develops as an adaptation mechanism. The association between gastric metaplasia and nonconventional and/or conventional dysplasia as precursors of colitis-associated colorectal cancer is unknown. To address this question, we retrospectively reviewed a series of 33 IBD colectomies to identify gastric metaplasia in 76 precursor lesions. We obtained 61 nonconventional and 15 conventional dysplasias. Among nonconventional dysplasia, 31 (50.8 %) were low-grade (LGD), 4 (6.5 %) were high-grade (HGD), 9 (14.8 %) had both LGD and HGD, and 17 (27.9 %) had no dysplasia (ND), while 14 (93 %) conventional dysplasias had LGD, and 1 (7 %) had LGD and HGD. Gastric metaplasia was assessed by concomitant immunoexpression of MUC5AC and loss of CDX2 staining. Expression of a p53-mut pattern was considered as a surrogate for gene mutation, and complete loss of MLH1 staining as presence of MLH1 hypermethylation. In nonconventional dysplasia, MUC5AC immunoexpression decreased as the degree of dysplasia increased, being 78 % in LGD and 39 % in HGD (p = 0.006). CDX2 was lost in epithelial glands with high expression of MUC5AC (p < 0.001). The p53-mut pattern was observed in 77 % HGD, 45 % LGD, and in 6 % with ND (p < 0.001). Neither nonconventional nor conventional dysplasia showed complete loss of MLH1 staining. Gastric metaplasia was also present in mucosa adjacent to nonconventional dysplasia with chronic changes or active inflammation. Our results show that gastric metaplasia appears in IBD-inflamed colon mucosa, it is the substrate of most nonconventional dysplasia and occurs prior to p53 alterations.

Characteristics, Reporting, and Potential Clinical Significance of Nonconventional Dysplasia in Inflammatory Bowel Disease

The term nonconventional dysplasia has been coined to describe several underrecognized morphologic patterns of epithelial dysplasia in inflammatory bowel disease (IBD), but to date, the full recognition of these newly characterized lesions by pathologists is uneven. The identification of nonconventional dysplastic subtypes is becoming increasingly important, as they often present as invisible/flat dysplasia and are more frequently associated with advanced neoplasia than conventional dysplasia on follow-up. This review describes the morphologic, clinicopathologic, and molecular characteristics of seven nonconventional subtypes known to date, as well as their potential significance in the clinical management of IBD patients.

Incidental Dysplasia During Total Proctocolectomy With Ileoanal Pouch: Is It Associated With Worse Outcomes?

BACKGROUND

Patients with inflammatory bowel disease (IBD) are at increased risk of colorectal cancer. In cases of invisible or nonendoscopically resectable dysplasia found at colonoscopy, total proctocolectomy with ileal pouch anal anastomosis can be offered with good long-term outcomes; however, little is known regarding cancer-related outcomes when dysplasia is found incidentally after surgery on final pathology.

METHODS

Using our prospectively collected pouch registry, we identified patients who had preoperative colonic dysplasia or dysplasia found only after colectomy. Patients with cancer preoperatively or after colectomy were excluded. Included patients were divided into 3 groups: PRE (+preoperative biopsy, negative final pathology), BOTH (+preoperative biopsy and final pathology), and POST (negative preoperative biopsy, +final pathology). Long-term outcomes in the 3 groups were assessed.

RESULTS

In total, 517 patients were included: PRE = 125, BOTH = 254, POST = 137. After a median follow-up of 12 years (IQR 3-21), there were no differences in overall, disease-free, or pouch survival between groups. Cancer/dysplasia developed in 11 patients: 3 (2%) in the PRE, 5 (2%) in the BOTH, and 3 (2%) in the POST group. Only 1 cancer-related death occurred in the entire cohort (PRE group). Disease-free survival at 10 years was 98% for all groups (P = .97). Pouch survival at 10 years was 96% for PRE, 99% for BOTH, and 97% for POST (P = .24).

CONCLUSIONS

The incidental finding of dysplasia on final pathology after proctocolectomy was not associated with worsened outcomes compared with preoperatively diagnosed dysplasia.

Berberine Depresses Inflammation and Adjusts Smooth Muscle to Ameliorate Ulcerative Colitis of Cats by Regulating Gut Microbiota

Intestinal microbiota dysbiosis is a well established characteristic of ulcerative colitis (UC). Regulating the gut microbiota is an effective UC treatment strategy. Berberine (BBR), an alkaloid extracted from several Chinese herbs, is a common traditional Chinese medicine. To establish the efficacy and mechanism of action of BBR, we constructed a UC model using healthy adult shorthair cats to conduct a systematic study of colonic tissue pathology, inflammatory factor expression, and gut microbiota structure. We investigated the therapeutic capacity of BBR for regulating the gut microbiota and thus work against UC in cats using 16S rRNA genes amplicon sequencing technology. Our results revealed that dextran sulfate sodium (DSS)-induced cat models of UC showed weight loss, diarrhea accompanied by mucous and blood, histological abnormalities, and shortening of the colon, all of which were significantly alleviated by supplementation with BBR. A 16S rRNA gene-based microbiota analysis demonstrated that BBR could significantly benefit gut microbiota. Western blot, quantitative PCR, and enzyme-linked immunosorbent assays (ELISAs) showed that in DSS-induced cat models, the expression of the inflammatory factors was increased, activating the JAK2/STAT3 signaling pathway, and treatment with BBR reversed this effect. The myosin light chain (MLC) phosphorylation in the smooth muscle of the intestines is associated with motility of inflammation-related diarrhea in cats. This study used gut flora analyses to demonstrate the anti-UC effects of BBR and its potential therapeutic mechanisms and offers novel insights into the prevention of inflammatory diseases using natural products. IMPORTANCE Ulcerative colitis (UC) is common in clinics. Intestinal microbiota disorder is correlated with ulcerative colitis. Although there are many studies on ulcerative colitis in rats, there are few studies on colitis in cats. Therefore, this study explored the possibility of the use of BBR as a safe and efficient treatment for colitis in cats. The results demonstrated the therapeutic effects of BBR on UC based on the state of the intestinal flora. The study found BBR supplementation to be effective against dextran sulfate sodium (DSS)-induced colitis, smooth muscle damage, and gut microbiota dysbiosis.