Traditional serrated adenoma-like lesions in patients with inflammatory bowel disease

Inflammatory bowel disease-associated serrated lesions with dysplasia are frequently associated with advanced neoplasia: supporting a unified classification approach

AIMS

Inflammatory bowel disease (IBD)-associated serrated lesions are categorized into three distinct subtypes: traditional serrated adenoma (TSA)-like lesion, sessile serrated lesion (SSL)-like lesion, and serrated lesion, not otherwise specified (NOS). Although the risk of neoplastic progression of serrated lesions without dysplasia has not been shown to exceed that of sporadic cases, the clinicopathologic features of the three serrated subtypes with dysplasia remain poorly understood in the context of IBD.

METHODS AND RESULTS

We analysed 87 serrated lesions with dysplasia (collectively referred to as serrated dysplasia) identified endoscopically in 58 IBD patients, including 51 (59%) TSA-like dysplasia, 24 (28%) SSL-like dysplasia, and 12 (14%) serrated dysplasia NOS. Inclusion criteria required all three serrated subtypes to show morphologic evidence of dysplasia and to be located within areas of colitis. We also compared the clinicopathologic features of serrated dysplasia with those of 239 conventional (adenomatous) dysplastic lesions from 149 IBD patients. The cohort included 39 (67%) men and 19 (33%) women, with a mean age of 54 years and a mean IBD duration of 20 years. Most patients had ulcerative colitis (n = 41; 71%) and pancolitis (n = 48; 83%). The majority of serrated lesions with dysplasia had a polypoid or visible endoscopic appearance (n = 73; 84%), with a mean size of 1.4 cm, and were found in the left colon (n = 66; 76%). Most lesions (n = 73; 84%) demonstrated low-grade dysplasia at the time of biopsy diagnosis, whereas high-grade dysplasia (HGD) was identified in the remaining 14 (16%) lesions. SSL-like dysplasia was more frequently associated with ulcerative colitis (94%) compared to TSA-like dysplasia (67%) and serrated dysplasia NOS (56%) (P = 0.042). Although only seven (12%) patients had a concurrent history of primary sclerosing cholangitis, it was exclusively identified in the TSA-like dysplasia group (19% versus 0% in both the SSL-like dysplasia group and the serrated dysplasia NOS group; P = 0.017). Serrated dysplasia NOS more commonly demonstrated HGD at the time of biopsy diagnosis (42%) compared to TSA-like dysplasia (12%) and SSL-like dysplasia (13%) (P = 0.022). Serrated dysplasia NOS was also more frequently associated with synchronous and/or metachronous nonconventional dysplasia (60%) compared to TSA-like dysplasia (16%) and SSL-like dysplasia (9%) (P = 0.037). Serrated dysplasia, regardless of subtype, was associated with high rates of advanced neoplasia (HGD or colorectal cancer) at the previous biopsy site or in the same colonic segment during follow-up. Within a mean follow-up time of 13 months, advanced neoplasia was detected in 50% of the TSA-like dysplasia group, 67% of the SSL-like dysplasia group, and 100% of the serrated dysplasia NOS group (P = 0.622). Moreover, at least one-third of patients in each group (58% in the TSA-like dysplasia group, 44% in the SSL-like dysplasia group, and 33% in the serrated dysplasia NOS group; P = 0.332) developed synchronous/metachronous dysplasia, with at least 50% of these lesions progressing to advanced neoplasia within a mean follow-up time of 11 months (P = 1.000). The serrated dysplasia group showed nearly six times the incidence of advanced neoplasia upon follow-up (59%) compared to the conventional dysplasia group (10%) (P < 0.001).

CONCLUSION

TSA-like dysplasia, SSL-like dysplasia, and serrated dysplasia NOS show distinct clinicopathologic features. However, all three serrated subtypes were associated with high rates of advanced neoplasia (50%-100%) during follow-up, suggesting that these lesions could potentially be combined into one diagnostic category, such as serrated dysplasia.

Examination of non-conventional dysplasias adjacent to colorectal adenocarcinoma in patients with IBD

Objective

Recently, several non-conventional variants of IBD-associated dysplasia have been described; however, their prevalence in Central-Eastern Europe is unknown. We aimed to perform a retrospective pilot study by re-evaluating several IBD-associated adenocarcinoma cases to survey the incidence of adjacent non-conventional dysplasia and validate that recent North American findings may apply to a European population.

Methods

Retrospectively, 28 randomly chosen cases of IBD-associated adenocarcinomas diagnosed between 2010 and 2022 were re-evaluated. The patient's sex, age (at the diagnosis of IBD and neoplasia), type of IBD, type of specimen [biopsy (n = 8)/surgical specimen (n = 20)], histological type, grade, localisation, stage, disease-free (DFS) and overall survival (OS) were obtained. Statistical analyses were carried out by using Mann-Whitney (continuous variables), Fisher's exact (categorical variables), Kaplan-Meier (DFS/OS curves), and logrank test (survival curves).

Results

Exclusively, conventional dysplasia was observed in 11, and non-conventional dysplasia in 8 patients. Combined conventional and non-conventional dysplasia was detected in 9 patients. Non-conventional dysplasia showing a combination of multiple subtypes was noted in 10 cases. Altogether, 25 non-conventional dysplastic foci were identified, which were diagnosed as hypermucinous (n = 9), goblet cell-deficient (n = 6), serrated not otherwise specified (NOS) (n = 6), and traditional serrated adenoma-like (n = 4). The majority of non-conventional dysplasias were associated with ulcerative colitis (n = 12). Mucinous adenocarcinoma was exclusively associated with non-conventional dysplasia, while medullary carcinoma was only with conventional dysplasias (p = 0.014 and 0.041).

Conclusion

Based on our results, non-conventional dysplasia is common (60%) adjacent to IBD-associated adenocarcinomas in a Central-Eastern European population and may be detected in biopsies. As multiple recent publications reported evidence of a worse prognosis and more common flat morphology compared to conventional dysplasias, their recognition is of great importance, and stricter follow-up with random biopsy samples may be considered.

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.

IDH1-mutated Crohn's disease-associated small bowel adenocarcinomas: Distinctive pathological features and association with MGMT methylation and serrated-type dysplasia

AIMS

Patients with Crohn's disease (CrD) have an elevated risk for the development of small bowel adenocarcinomas (SBAs). Actionable isocitrate dehydrogenase 1 (IDH1) mutations have been reported to be more frequent in CrD-SBAs than in sporadic SBAs. The present study aimed to investigate the clinicopathological and immunophenotypical features, as well as methylation profiles, of IDH1-mutated CrD-SBAs.

METHODS AND RESULTS

An international multicentre series of surgically resected CrD-SBAs was tested for IDH1 mutation. Clinicopathological features, immunophenotypical marker expression and O6-methylguanine-DNA methyltransferase (MGMT) and long interspersed nuclear element-1 (LINE-1) methylation were compared between IDH1-mutated and IDH1 wild-type CrD-SBAs. Ten (20%) of the 49 CrD-SBAs examined harboured an IDH1 mutation and all the mutated cancers harboured the R132C variant. Compared to IDH1 wild-type cases, IDH1-mutated CrD-SBAs showed significantly lower rates of cytokeratin 7 expression (P = 0.005) and higher rates of p53 overexpression (P = 0.012) and MGMT methylation (P = 0.012). All three dysplastic growths associated with IDH1-mutated SBAs harboured the same IDH1 variant (R132C) of the corresponding invasive cancer, and all were of non-conventional subtype (two serrated dysplastic lesions and one goblet cell-deficient dysplasia). In particular, non-conventional serrated dysplasia was significantly associated with IDH1-mutated CrD-SBAs (P = 0.029). No significant cancer-specific survival difference between IDH1-mutated CrD-SBA patients and IDH1 wild-type CrD-SBA patients was found (hazard ratio = 0.55, 95% confidence interval = 0.16-1.89; P = 0.313).

CONCLUSIONS

IDH1-mutated CrD-SBAs, which represent approximately one-fifth of total cases, are characterised by distinctive immunophenotypical features and methylation profiles, with potential therapeutic implications. Moreover, IDH1-mutated non-conventional, serrated dysplasia is likely to represent a precursor lesion to such CrD-SBAs.

Recently described types of dysplasia associated with IBD: tips and clues for the practising pathologist

Longstanding inflammatory bowel disease (especially in patients with severely active disease or primary sclerosing cholangitis) is associated with an increased risk of developing dysplasia and adenocarcinoma. This review covers critical clinical aspects, such as risk factors and screening endoscopy basics, emphasising the SCENIC (Surveillance for Colorectal Endoscopic Neoplasia Detection in Inflammatory Bowel Disease International Consensus) guidelines. The histopathological and molecular features of both conventional (adenomatous) dysplasia and the non-conventional subtypes (hypermucinous dysplasia, goblet cell-deficient dysplasia, crypt cell dysplasia, serrated dysplasias) are discussed with an emphasis on challenging diagnostic areas and helpful tips to allow correct categorisation by the practising pathologist.

Serrated polyps in patients with ulcerative colitis: Unique clinicopathological and biological characteristics

BACKGROUND

Serrated polyps have recently been reported in patients with ulcerative colitis (UC); however, their prevalence and detailed characteristics remain unclear.

METHODS

The prevalence and clinicopathological and biological characteristics of serrated polyps in patients with UC were retrospectively examined in a single tertiary inflammatory bowel disease center in Japan from 2000 to 2020.

RESULTS

Among 2035 patients with UC who underwent total colonoscopy, 252 neoplasms, including 36 serrated polyps (26 in colitis-affected segments, 10 in colitis-unaffected segments), were identified in 187 patients with UC. The proportion of serrated polyps was 1.8% (36/2035). Serrated polyps in colitis-affected segments were common with extensive colitis (88%), history of persistent active colitis (58%), and long UC duration (12.1 years). Serrated polyps in colitis-affected segments were more common in men (88%). Of the 26 serrated polyps in colitis-affected segments, 15, 6, and 5 were categorized as sessile serrated lesion-like dysplasia, traditional serrated adenoma-like dysplasia, and serrated dysplasia not otherwise specified, respectively. Sessile serrated lesion-like dysplasia was common in the proximal colon (67%) and with BRAF mutation (62%), whereas traditional serrated adenoma-like dysplasia and serrated dysplasia not otherwise specified were common in the distal colon (100% and 80%, respectively) and with KRAS mutations (100% and 75%, respectively).

CONCLUSIONS

Serrated polyps comprised 14% of the neoplasias in patients with UC. Serrated polyps in colitis-affected segments were common in men with extensive and longstanding colitis, suggesting chronic inflammation in the development of serrated polyps in patients with UC.

Exploring the spectrum of serrated epithelium encountered in inflammatory bowel disease

Patients with inflammatory bowel disease (IBD) are at an increased risk for colorectal cancer. Currently, dysplasia is the best marker of CRC risk. Assessing dysplasia is a challenging task for pathologists as the longstanding inflammation causes marked reactive cytologic changes and architectural distortion. Recent descriptions of nonconventional types of dysplasia in IBD have added to the complexity. In this review, we focus on the clinical, endoscopic, histologic, and molecular findings in lesions with serrated epithelium. Serrated epithelial change (SEC), sessile serrated lesion (SSL)-like, serrated lesion-not otherwise specified (SL-NOS), and traditional serrated adenoma (TSA)-like lesions all typically occur in patients with longstanding IBD with mean ages in the fifth-sixth decade. SEC is often encountered in nontargeted biopsies while the others form visible polyps. While serrated lesions have significant histologic overlap, subtle differences can help pathologists separate them. SEC has markedly distorted architecture with crypts losing perpendicular orientation to the muscularis mucosae. The crypts are goblet cell-rich and have irregular serrations that involve the full length of the crypt. SSL-like lesions are goblet cell poor and have microvesicular cytoplasm. Like their sporadic counterpart in non-IBD patients, these lesions have lateral growth at the crypt bases. TSA-like lesions are characterized by their villous architecture, ectopic crypts, pink cytoplasm, and hyperchromatic elongated nuclei. We also explore molecular findings that help in distinguishing these lesions, current knowledge on the association of each of these lesions with dysplasia and CRC, and future research needed to better characterize these entities.

Sampling and Reporting of Inflammatory Bowel Disease

Pathologists have an important and expanding role in the diagnosis and management of inflammatory bowel disease. This role includes the initial diagnosis of the disease, assessment of the response to treatment and the identification of short-term complications such as cytomegalovirus infection and long-term complications such as dysplasia. Furthermore, the assessment of resection specimens for complication of disease is important to determining the risk of subsequent disease or inflammation within an ileal pouch. Adequate sampling of the disease at endoscopy and from the surgical resection specimen is vital to determining the ultimate information that can be provided by the pathologist. This sampling is determined by the clinical scenario. Similarly, a standardized approach to reporting and synthesizing the histologic findings will improve patient management. This is best exemplified by the increasing interest in histologic activity indices, such as the Nancy index in ulcerative colitis, and in the standardized reporting for inflammatory bowel disease dysplasia recommended by the SCENIC international consensus.

Increased Colorectal Neoplasia Risk in Patients with Inflammatory Bowel Disease and Serrated Polyps with Dysplasia

BACKGROUND

The impact of serrated polyps on the advanced colorectal neoplasia (CRN) risk in inflammatory bowel disease (IBD) patients is unknown. Serrated polyps are histologically categorized as hyperplastic polyps (HPs), sessile serrated lesions (SSLs), and traditional serrated adenomas (TSAs).

AIMS

We aimed (1) to characterize the serrated polyps in IBD patients, (2) to identify factors associated with the presence of serrated polyps in IBD, and (3) to assess the CRN risk in IBD patients with serrated polyps.

METHODS

We established a retrospective cohort of IBD patients with and without colonic serrated polyps. Cox-regression analysis with time-dependent variables was used to compare advanced CRN risk in IBD patients with and without serrated polyps.

RESULTS

Of the 621 enrolled IBD patients, 198 had a serrated polyp (92 HPs, 88 SSLs without dysplasia, 13 SSLs with dysplasia, and 5 TSAs). Independent factors associated with serrated polyps were ulcerative colitis (UC) (odds ratio (OR) 1.77, 95% confidence interval (CI) 1.19-2.62, p = 0.005), male gender (OR 1.63, 95% CI 1.11-2.40, p = 0.013), and older age (per year increase, OR 1.06, 95%CI 1.05-1.08, p < 0.001). TSAs and SSLs with dysplasia were risk factors for subsequent advanced CRN (HR 13.51, 95% CI 3.11-58.68, p < 0.001), while HPs (HR 1.98, 95% CI 0.46-8.60, p = 0.36) and SSLs without dysplasia (HR 0.87, 95% CI 0.11-6.88, p-0.89) did not impact the subsequent advanced CRN risk.

CONCLUSIONS

UC, male gender and older age were associated with the presence of serrated polyps. The majority of serrated polyps (91%) were HPs and SSL without dysplasia and did not affect the CRC risk. However TSAs and SSLs with dysplasia, representing a small subgroup of serrated polyps (9%), were associated with subsequent advanced CRN.

ECCO Topical Review Optimising Reporting in Surgery, Endoscopy, and Histopathology

BACKGROUND AND AIMS

Diagnosis and management of inflammatory bowel diseases [IBD] requires a lifelong multidisciplinary approach. The quality of medical reporting is crucial in this context. The present topical review addresses the need for optimised reporting in endoscopy, surgery, and histopathology.

METHODS

A consensus expert panel consisting of gastroenterologists, surgeons, and pathologists, convened by the European Crohn's and Colitis Organisation, performed a systematic literature review. The following topics were covered: in endoscopy: [i] general IBD endoscopy; [ii] disease activity and surveillance; [iii] endoscopy treatment in IBD; in surgery: [iv] medical history with surgical relevance, surgical indication, and strategy; [v] operative approach; [vi] intraoperative disease description; [vii] operative steps; in pathology: [viii] macroscopic assessment and interpretation of resection specimens; [ix] IBD histology, including biopsies, surgical resections, and neoplasia; [x] IBD histology conclusion and report. Statements were developed using a Delphi methodology incorporating two consecutive rounds. Current practice positions were set when ≥ 80% of participants agreed on a recommendation.

RESULTS

Thirty practice positions established a standard terminology for optimal reporting in endoscopy, surgery, and histopathology. Assessment of disease activity, surveillance recommendations, advice to surgeons for operative indication and strategies, including margins and extent of resection, and diagnostic criteria of IBD, as well as guidance for the interpretation of dysplasia and cancer, were handled. A standardised report including a core set of items to include in each specialty report, was defined.

CONCLUSIONS

Interdisciplinary high-quality care requires thorough and standardised reporting across specialties. This topical review offers an actionable framework and practice recommendations to optimise reporting in endoscopy, surgery, and histopathology.

Targeted next-generation sequencing supports serrated epithelial change as an early precursor to inflammatory bowel disease-associated colorectal neoplasia

Serrated epithelial change (SEC) manifests in patients with long-standing inflammatory bowel disease (IBD) and is characterized by disorganized crypt architecture, irregular serrations, and goblet cell-rich epithelium. The serrated nature of SEC is reminiscent of serrated colorectal polyps, which frequently harbor KRAS/BRAF mutations. SEC is, however, not only histologically distinct from sporadic serrated polyps but also associated with colorectal neoplasia. Whether SEC is a precursor to IBD-associated neoplasia remains unclear. To further define the relationship of SEC with serrated colorectal polyps and IBD-associated neoplasia, we performed targeted next-generation sequencing on colorectal specimens to include the following: SEC without dysplasia/neoplasia (n = 10), SEC with separate foci of associated dysplasia/adenocarcinoma from the same patients (n = 17), and uninvolved mucosa (n = 10) from 14 patients. In addition, we molecularly profiled sessile serrated lesion (SSL)-like or serrated lesion, not otherwise specified (SL-NOS), specimens, from 11 patients who also had IBD. This control cohort included SSL-like/SL-NOS without dysplasia/neoplasia (n = 11), SSL-like/SL-NOS with associated low-grade dysplasia (n = 2), and uninvolved mucosa (n = 8). By next-generation sequencing, the most frequently mutated gene in SEC without neoplasia and associated dysplasia/adenocarcinoma from separate foci in the same patients was TP53. Recurrent TP53 mutations were present in 50% of SEC specimens without dysplasia/neoplasia. In addition, alterations in TP53 were detected at a prevalence of 71% in low-grade dysplasia, 83% in high-grade dysplasia, and 100% in adenocarcinoma. Paired sequencing of SEC and associated neoplasia revealed identical TP53 missense mutations for 3 patients. In contrast, 91% of SSL-like/SL-NOS specimens without dysplasia/neoplasia harbored KRAS/BRAF mutations, which were conserved in associated low-grade dysplasia. No genomic alterations were found in uninvolved mucosa from either patients with SEC or patients with SSL-like/SL-NOS. Based on our findings, we conclude SEC is distinct from SSL-like serrated colorectal lesions in patients with IBD and an early precursor to IBD-associated neoplasia that warrants colonoscopic surveillance.

Serrated Lesions in Inflammatory Bowel Disease: Genotype-Phenotype Correlation

BACKGROUND

Patients with inflammatory bowel disease (IBD) and hyperplastic/serrated polyposis have an increased risk of colorectal cancer. The aim of our study was to elucidate the nature of serrated lesions in IBD patients.

MATERIALS AND METHODS

Sixty-five lesions with serrated morphology were analyzed in 39 adult IBD patients. Lesions were classified according to the WHO 2019 criteria or regarded as reactive, and molecular analysis was performed.

RESULTS

82.1% of patients had ulcerative colitis, 17.9% had Crohn's disease; 51.3% were female, and the mean age was 54.5 years. The duration of IBD varied significantly (16.7 ± 11.4 years). Endoscopy showed polypoid lesions in 80.3%; the size ranged from 2 to 20 mm. A total of 21.6% of the lesions were located in the right colon. Five lesions were classified as inflammatory pseudopolyps, 28 as hyperplastic polyp, 21 and 2 as sessile serrated lesion without and with dysplasia, respectively, and 9 as traditional serrated adenoma with low-grade dysplasia. Analysis of all true serrated lesions revealed 31 mutations in KRAS and 32 in BRAF gene. No mutations were identified in inflammatory pseudopolyps. In the right colon BRAF mutations were more frequent than KRAS (16 vs 3), while KRAS mutations prevailed on the left side (28 vs 16, P < .001). One patient with traditional serrated adenomas progressed to an adenocarcinoma after 61 months.

CONCLUSION

The molecular analysis could help discriminate true serrated lesions (IBD-associated or not) from reactive pseudopolyps with serrated/hyperplastic epithelial change. These should help in more accurate classification of serrated lesions.