Mucosal healing is the mainstream goal of modern treat-to-target strategy as it is associated with a significantly more favorable disease course in IBD patients with either ulcerative colitis or Crohn's disease. Recent advances in endoscopic imaging technologies have overcome the traditional concept of mucosal healing assessed with conventional white light imaging, allowing for multiple levels of endoscopic healing up to the boundaries of molecular and functional evaluation. In this review, we focused on conventional and emerging strategies to assess endoscopic healing in ulcerative colitis and ileocolonic Crohn's disease, examining their pros and cons in real life practice.

The diagnostic accuracy of Narrow Band Imaging (NBI) in the endoscopic surveillance of ulcerative colitis (UC) has been disappointing in most trials which used the Kudo classification. We aim to compare the performance of NBI in the lesion characterization of UC, when applied according to three different classifications (NICE, Kudo, Kudo-IBD).

In a prospective, real-life study, all visible lesions found during consecutive surveillance colonoscopies with NBI (Exera-II CV-180) for UC were classified as suspected or non-suspected for neoplasia according to the NICE, Kudo and Kudo-IBD criteria. The sensitivity (SE), specificity (SP), positive (+LR) and negative (-LR) likelihood ratios of the three classifications were calculated, using histology as the reference standard.

394 lesions (mean size 6 mm, range 2-40 mm) from 84 patients were analysed. Twenty-one neoplastic (5%), 49 hyperplastic (12%), and 324 inflammatory (82%) lesions were found. The diagnostic accuracy of the NICE, Kudo and Kudo-IBD classifications were, respectively: SE 76%-71%-86%; SP 55-69%-79% (p < 0.05 Kudo-IBD vs. both Kudo and NICE); +LR 1.69-2.34-4.15 (p < 0.05 Kudo-IBD vs. both Kudo and NICE); -LR 0.43-0.41-0.18.

The diagnostic accuracy of NBI in the differentiation of neoplastic and non-neoplastic lesions in UC is low if used with conventional classifications of the general population, but it is significantly better with the modified Kudo classification specific for UC.

Current guidelines strongly recommend the use of validated classifications to support optical diagnosis of lesions with advanced endoscopic imaging in the lower gastrointestinal tract. However, the optimal strategy in inflammatory bowel disease (IBD) is still a matter of debate.

To analyze the accuracy of endoscopic classifications or single predictors for in vivo lesion characterization during endoscopic surveillance of IBD with advanced endoscopic imaging.

Systematic review.

Medline and PubMed were used to extract all studies which focused on lesion characterization of neoplastic and non-neoplastic lesions in IBD. The diagnostic accuracy of endoscopic classifications and single endoscopic predictors for lesion characterization were analyzed according to type of patients, lesions, and technology used. When available, the rates of true and false positives or negatives for neoplasia were pooled and the sensitivity (SE), specificity (SP), positive predictive value, and negative predictive value (NPV) were calculated.

We included 35 studies (2789 patients; 5925 lesions - 1149 neoplastic). Advanced endoscopic imaging included dye-based chromoendoscopy, virtual chromoendoscopy (VCE), magnification and high-definition endoscopy, confocal laser endomicroscopy (CLE), endocytoscopy, and autofluorescence imaging. The Kudo classification of pit patterns was most frequently used, with pooled SE 83%, SP 83%, and NPV 95%. The endoscopic criteria with the highest accuracy, with minimum SE ⩾ 90%, SP ⩾ 80%, and NPV ⩾ 90% were: the Kudo-IBD classification used with VCE (Fuji Intelligent Color Enhancement and i-SCAN); combined irregular surface and vascular patterns used with narrow band imaging; the Mainz classification used with CLE. Multiple clinical and technical factors were found to influence the accuracy of optical diagnosis in IBD.

No single endoscopic factor has yet shown sufficient accuracy for lesion characterization in IBD surveillance. Conventional classifications developed in the non-IBD setting have lower accuracy in IBD. The use of new classifications adapted for IBD (Kudo-IBD), and new technologies based on in vivo microscopic analysis show promise.

Advances in endoscopic technology, including magnifying and image-enhanced techniques, have been attracting increasing attention for the optical characterization of colorectal lesions. These techniques are being implemented into clinical practice as cost-effective and real-time approaches. Additionally, with the recent progress in endoscopic interventions, endoscopic resection is gaining acceptance as a treatment option in patients with ulcerative colitis (UC). Therefore, accurate preoperative characterization of lesions is now required. However, lesion characterization in patients with UC may be difficult because UC is often affected by inflammation, and it may be characterized by a distinct "bottom-up" growth pattern, and even expert endoscopists have relatively little experience with such cases. In this systematic review, we assessed the current status and limitations of the use of optical characterization of lesions in patients with UC.

A literature search of online databases (MEDLINE via PubMed and CENTRAL via the Cochrane Library) was performed from 1 January 2000 to 30 November 2021.

The database search initially identified 748 unique articles. Finally, 25 studies were included in the systematic review: 23 focused on differentiation of neoplasia from non-neoplasia, one focused on differentiation of UC-associated neoplasia from sporadic neoplasia, and one focused on differentiation of low-grade dysplasia from high-grade dysplasia and cancer.

Optical characterization of neoplasia in patients with UC, even using advanced endoscopic technology, is still challenging and several issues remain to be addressed. We believe that the information revealed in this review will encourage researchers to commit to the improvement of optical diagnostics for UC-associated lesions.

It is unclear whether the Japan Narrow-Band Imaging Expert Team (JNET) classification and pit pattern classification are applicable for diagnosing neoplastic lesions in patients with ulcerative colitis (UC).

To clarify the diagnostic performance of these classifications for neoplastic lesions in patients with UC.

This study was conducted as a single-center, retrospective case-control study. Twenty-one lesions in 19 patients with UC-associated neoplasms (UCAN) and 23 lesions in 22 UC patients with sporadic neoplasms (SN), evaluated by magnifying image-enhanced endoscopy, were retrospectively and separately assessed by six endoscopists (three experts, three non-experts), using the JNET and pit pattern classifications. The results were compared with the pathological diagnoses to evaluate the diagnostic performance. Inter- and intra-observer agreements were calculated.

In this study, JNET type 2A and pit pattern type III/IV were used as indicators of low-grade dysplasia, JNET type 2B and pit pattern type VI low irregularity were used as indicators of high-grade dysplasia to shallow submucosal invasive carcinoma, JNET type 3 and pit pattern type VI high irregularity/VN were used as indicators of deep submucosal invasive carcinoma. In the UCAN group, JNET type 2A and pit pattern type III/IV had a low positive predictive value (PPV; 50.0% and 40.0%, respectively); however, they had a high negative predictive value (NPV; 94.7% and 100%, respectively). Conversely, in the SN group, JNET type 2A and pit pattern type III/IV had a high PPV (100% for both) but a low NPV (63.6% and 77.8%, respectively). In both groups, JNET type 3 and pit pattern type VI-high irregularity/VN showed high specificity. The inter-observer agreement of JNET classification and pit pattern classification for UCAN among experts were 0.401 and 0.364, in the same manner for SN, 0.666 and 0.597, respectively. The intra-observer agreements of JNET classification and pit pattern classification for UCAN among experts were 0.387, 0.454, for SN, 0.803 and 0.567, respectively.

The accuracy of endoscopic diagnosis using both classifications was lower for UCAN than for SN. Endoscopic diagnosis of UCAN tended to be underestimated compared with the pathological results.

Patients with ulcerative colitis (UC) have an increased risk of colorectal cancer. Some studies have recently investigated endoscopic resection of UC-associated neoplasia (UCAN), but the indications for endoscopic resection of UCAN remain controversial. This study sought to clarify the problems encountered in endoscopic submucosal dissection (ESD) for UCAN.

Seventeen lesions in 12 patients with UCAN (UCAN group) and 913 epithelial lesions in 824 control patients without UC (non-UC group) were evaluated. Both groups underwent ESD between January 2010 and December 2017 at Toranomon Hospital, Tokyo, Japan. Treatment outcomes of the 2 groups were compared retrospectively.

Univariate analysis showed that the mean tumor size was significantly smaller in the UCAN group than in the non-UC group (25.1 ± 26.7 mm vs. 31.9 ± 19.0; p = 0.0023); however, the R0 resection rate was significantly lower in the UCAN group (70.6 vs. 92.9%; p = 0.001). Multivariate analysis showed a significantly lower negative horizontal margin rate in the UCAN group (odds ratio 11.3, 95% confidence interval 3.588-34.525; p = 0.000).

ESD for UCAN is associated with a low-negative horizontal margin rate. When performing ESD for UCAN, it is important to evaluate the accuracy of the UCAN demarcation line, especially for flat lesions, using white-light imaging and chromoendoscopy as well as other modalities, including biopsy of surrounding tissues.

In the treatment of ulcerative colitis (UC), accurate evaluation of UC activity is important to achieve mucosal healing. We sought to investigate the clinical utility of linked color imaging (LCI) for the evaluation of endoscopic activity and prediction of relapse in UC patients.

We enrolled 72 consecutive UC patients in remission who underwent colonoscopy at our institution between September 2016 and October 2018. The relationship between the presence of redness in white light imaging (WLI) and LCI and histopathological inflammation (Geboes score: GS) at 238 biopsy sites was examined. We also assessed the presence or absence of planar redness in the entire rectum as ± and classified the patients into three groups according to the combination of WLI/LCI: A: WLI-/LCI-, B: WLI-/LCI+, and C: WLI+/LCI+. The relationship between WLI/LCI classification and relapse in 64 patients followed up for more than 12 months from initial colonoscopy was assessed and compared to the Mayo endoscopic subscore (MES).

A GS of 0 or 1 accounted for 89% of WLI/LCI non-redness sites, while a GS of 2 or 3 accounted for 42% of WLI non-redness/LCI redness sites. LCI findings were significantly correlated with GS. During follow-up, 10 patients in group C and four patients in group B relapsed, but none in group A. Non-relapse rates were significantly correlated with WLI/LCI classification, but not with MES.

LCI is a useful modality for accurate assessment of endoscopic activity and prediction of relapse in UC by detecting mild inflammation unrecognizable by WLI.

Colorectal neoplasias (CRN)s developing from the ulcerative colitis (UC) mucosa include both colitic and sporadic neoplasias. Although several genomic analyses of advanced colitis-associated cancer are available, such studies do not distinguish between colitic and sporadic cases, and the early-stage genomic alterations involved in the onset of colitic cancer remain unclear. To address this, we performed a genomic analysis of early-stage CRN developing from the UC mucosa (CRNUC).

We extracted DNA from 36 early-stage CRNUCs (T1 cancer, 10; dysplasia, 26) from 32 UC patients and performed targeted sequencing of 43 genes commonly associated with colitis-associated cancer and compared the results with sequencing data from the Japanese invasive colitis-associated cancer.

The most frequently mutated gene in the CRNUC cohort was APC (mutated in 47.2% of the cases), followed by TP53 (44.4%), KRAS (27.8%), and PRKDC (27.8%). None of the TP53 mutations occurred at any of the hotspot codons. Although the TP53 mutations in The Cancer Genome Atlas of Colorectal Cancer were dispersed throughout the gene, those detected here in CRNUC cases were concentrated in the amino terminal part of the DNA-binding domain. Interestingly, the mutations in KRAS and TP53 were mutually exclusive in CRNUC, and CRNUCs with KRAS mutations had histologically serrated lesions in the gland duct. Mayo endoscopic subscore was higher in TP53-mutated CRNUCs and lower in KRAS-mutated CRNUCs.

Our findings suggest that early-stage CRNUC can be classified into 2 groups: those developing through the carcinogenic pathway via TP53 mutations and those developing through the carcinogenic pathway via KRAS mutations.

Background and study aims  Virtual chromoendoscopy with Fuji Intelligent Color Enhancement (FICE) has never been studied in prospective trials of endoscopic surveillance for ulcerative colitis (UC). We compared FICE and white light endoscopy (WLE) in differentiation of visible lesions in UC. Patients and methods  In a prospective parallel study, we compared consecutive outpatients with UC submitted to surveillance colonoscopy with FICE or WLE. At least one visible polypoid or non-polypoid lesion for each patient was required. Random biopsies from normal mucosa, targeted biopsies or removal of suspected neoplastic lesions and targeted biopsies of unsuspected lesions were performed. In the FICE arm, neoplasia was suspected according to a modified Kudo classification (FICE-KUDO/inflammatory bowel disease [IBD]). Sensitivity (SE), specificity (SP), positive and negative likelihood ratios (LR) and negative predictive value (NPV) were analyzed. Results  One hundred patients were submitted to FICE (n = 46) or WLE (n = 54). Twenty-two patients (11 in WLE, 11 in FICE) had a least one neoplastic lesion. No neoplasia was found in random biopsies. Among 275 lesions, 17 of 136 by FICE and 27 of 139 by WLE were suspected neoplasia, but 28 (14 in each arm) were true neoplastic lesions. The accuracy of FICE-KUDO/IBD vs WLE (per lesion) was: SE 93 % vs 64 % ( P  = 0.065), SP 97 % vs 86 % ( P  = 0.002), positive-LR 28.3 vs 4.5 ( P  = 0.001), negative-LR 0.07 vs 0.42 ( P  = 0.092), NPV 99 % vs 96 % ( P  = 0.083). FICE-KUDO/IBD detected more non-polypoid lesions than WLE ( P  = 0.016). Conclusions  Targeted biopsies of polypoid and non-polypoid lesions, using the modified Kudo classification with FICE are more accurate than WLE in UC surveillance.

Early diagnosis of colitis-associated cancer and dysplasia through surveillance endoscopy is vital for patients with ulcerative colitis (UC). This study aimed to evaluate the efficacy of autofluorescence endoscopy (AFE) using 5-aminolevulinic acid (ALA) and to investigate the fluorescence signal localization pattern following 5-ALA administration in tumorous lesions diagnosed as colitis-associated cancer and dysplasia. The sensitivity and specificity of tumorous lesions detected by white light endoscopy (WLE) with and without AFE were evaluated.

Overall, 13 endoscopic procedures were performed in 11 patients with UC using WLE and AFE following the oral administration of 5-ALA. The biopsied lesions detected via endoscopy and resected specimens from cases underwent colectomy were assessed histopathologically. The sensitivity and specificity of detecting tumorous lesions by WLE with and without AFE were evaluated.

Of the 68 lesions detected and biopsied, 63 were detected via WLE, and five were detected via AFE alone. The sensitivity of detecting colitis-associated cancer and dysplasia via WLE combined with AFE was 36.4%, and the specificity, positive predictive value and negative predictive value were 94.2%, 57.1%, and 87.5%, respectively. Tumorous lesions displayed three types of fluorescence patterns on AFE.

AFE using 5-ALA can detect colitis-associated cancer and dysplasia in patients with long-standing UC and lesions that could not be detected via WLE. The distinctive fluorescence patterns in lesions may permit qualitative diagnoses of colitis-associated cancer and dysplasia.

The aim of this investigation was to evaluate the efficacy of Japanese magnifying colonoscopic classifications for ulcerative colitis-associated neoplasia (UCAN).

We reviewed the colonoscopy records from 2011 to 2018 at our institutions and identified cases of endoscopically or surgically resected UCAN observed by magnifying narrow-band imaging (NBI) endoscopy and magnifying chromoendoscopy. Association between magnifying endoscopic classification and histopathological findings was investigated retrospectively. Japan NBI expert team (JNET) classification and pit pattern classification were applied.

There were 17 patients who had a diagnosis of UCAN. Tumors of types 2A, 2B and 3 by JNET classification correlated with the histopathological findings of low-grade dysplasia (LGD)/high-grade dysplasia (HGD), HGD, and massively submucosal invasive (mSM) carcinoma, respectively. Tumors of types III/IV, V_I low irregularity, and V_I high irregularity/V_N by pit pattern classification were correlated with the histopathological findings of LGD/HGD, HGD, and mSM carcinoma, respectively.

Japan NBI expert team classification and pit pattern classification may be predictive of the histological diagnosis and invasion depth of UCAN. This needs to be investigated prospectively in a large cohort or in a randomized clinical trial.

The aim of this study was to analyze the performance of Fuji Intelligent Color Enhancement (FICE) using the classification of Kudo in the differentiation of neoplastic and non-neoplastic raised lesions in ulcerative colitis (UC).

The Kudo classification of mucosal pit patterns is an aid for the differential diagnosis of colorectal polyps in the general population, but no systematic studies are available for all forms of raised lesions in UC.

All raised, polypoid and nonpolypoid, lesions found during consecutive surveillance colonoscopies with FICE for long-standing UC were included. In the primary prospective analysis, the Kudo classification was used to predict the histology by FICE. In a post hoc analysis, further endoscopic markers were also explored.

Two hundred and five lesions (mean size, 8 mm; range, 2 to 30 mm) from 59 patients (mean age, 56 y; range, 21 to 79 y) were analyzed. Twenty-three neoplastic (11%), 18 hyperplastic (9%), and 164 inflammatory (80%) lesions were found. Thirty-one lesions (15%), none of which were neoplastic, were unclassifiable according to Kudo. After logistic regression, a strong negative association resulted between endoscopic activity and neoplasia, whereas the presence of a fibrin cap was significantly associated with endoscopic activity. Using FICE, the sensitivity, specificity, and positive and negative likelihood ratios of the Kudo classification were 91%, 76%, 3.8, and 0.12, respectively. The corresponding values by adding the fibrin cap as a marker of inflammation were 91%, 93%, 13, and 0.10, respectively.

FICE can help to predict the histology of raised lesions in UC. A new classification of pit patterns, based on inflammatory markers, should be developed in the setting of UC to improve the diagnostic performance.

During surveillance colonoscopy of patients with long-standing ulcerative colitis [UC], a variety of dysplastic and non-dysplastic lesions are detected. The aim of this study was to address the diagnostic accuracy of endoscopic characterization of endoscopic trimodal imaging [ETMI] and chromoendoscopy [CE]. ETMI includes the combination of autofluorescence imaging [AFI], narrow band imaging [NBI] and white light endoscopy [WLE].

This is a pre-specified additional analysis of a multi-centre, randomized controlled trial that compared AFI with CE for dysplasia detection in 210 patients with long-standing UC [FIND-UC trial]. In the AFI arm, endoscopists used the ETMI system to record AFI colour, Kudo pit pattern using NBI and WLE for lesion characterization. For AFI, purple colour and ambiguous colour combined with pit pattern type III-V on NBI was considered dysplastic. Kudo pit pattern was described in the CE arm. For pit pattern description using NBI and CE, type III-V was considered dysplastic. Histology was the reference standard.

In total, 52 dysplastic and 255 non-dysplastic lesions were detected. Overall sensitivity for real-time prediction of dysplasia was 76.9% (95% confidence interval [CI] 46.2-95.0) for ETMI, and 81.6% [95% CI 65.7-92.3] for CE. Overall negative predictive value [NPV] for ETMI was 96.9% [95% CI 92.0-98.8] and 94.7% [90.2-97.2] for CE.

Sensitivity for endoscopic differentiation of dysplastic lesions detected during surveillance of patients with long-standing UC seems limited using ETMI and CE. Future research is warranted as the high NPV indicates that these techniques are valuable for the exclusion of dysplastic lesions [NTR4062].

Background and study aims: Colitis-associated cancer/dysplasia (CC/D) can affect the life expectancy of patients with ulcerative colitis (UC). Although the utility of magnifying chromocolonoscopy has been shown, the use of optical magnification with narrow band imaging (NBI) for distinguishing CC/D from non-neoplastic lesions in patients with UC has not been reported. We evaluated whether endoscopic findings are distinguishing and thus assessed the clinical usefulness of NBI magnification for differentiating UC-associated lesions. Patients and methods: The study involved 27 patients diagnosed and treated at Hiroshima University Hospital between September 2005 and March 2015: a neoplasia group (16 lesions) and a non-neoplasia group (17 lesions). The neoplasias comprised 9 dysplastic lesions, 5 intramucosal carcinomas, and 2 submucosal carcinomas, and 17 non-neoplastic lesions. Targeted biopsy samples of suspicious lesions detected by conventional colonoscopy were classified pathologically as neoplastic or non-neoplastic, and NBI magnifying colonoscopy findings (i. e., the surface [unclear/regular/irregular/amorphous] and vascular [same as the background mucosa/regular/irregular/avascular] patterns) of the 2 lesion types were compared. Results: Irregular/amorphous surface patterns were significantly more common in neoplastic lesions than in non-neoplastic lesions (81 % [13/16] vs. 18 % [3/17], respectively, P < 0.001). Irregular/avascular vessel pattern tended to be more common in neoplastic lesions (75 % [12/16] vs. 41 % [7/17], respectively). The surface pattern correctly predicted 82 % of neoplastic lesions, and the vessel pattern correctly predicted 67 % of non-neoplastic lesions. The 2 endoscopic findings together correctly predicted 91 % of neoplastic lesions. Conclusion: Surface pattern, determined by magnifying colonoscopy with NBI, is useful for differenting between UC-associated neoplastic and non-neoplastic lesions.

Modern strategies for the treatment of ulcerative colitis require more accurate tools for gastrointestinal imaging to better assess mucosal disease activity and long-term prognostic clinical outcomes. Recent advances in gastrointestinal luminal endoscopy are radically changing the role of endoscopy in every-day clinical practice and research trials. Advanced endoscopic imaging techniques including high-definition endoscopes, optical magnification endoscopy, and various chromoendoscopy techniques have remarkably improved endoscopic assessment of ulcerative colitis. More recently, optical biopsy techniques with either endocytoscopy or confocal laser endomicroscopy have shown great potential in predicting several histological changes in real time during ongoing endoscopy. Here, we review current applications of advanced endoscopic imaging techniques in ulcerative colitis and present the most promising upcoming headways in this field.

Surgery aims to prevent cancer-related morbidity for patients with ulcerative colitis (UC) associated dysplasia. The literature varies widely regarding the likelihood of dysplastic progression to higher grades of dysplasia or cancer. The aim of this study was to characterize the likelihood of the development of colorectal cancer (CRC) of patients with UC-associated dysplasia who chose to defer surgery.

A retrospective review was carried out of patients undergoing surgery for UC at the Mayo Clinic, who were diagnosed to have dysplasia between August 1993 and July 2012. The relationships between grade of dysplasia, time to surgery and the detection of unsuspected carcinoma were investigated.

In all, 175 patients underwent surgery at a median of 4.9 (interquartile range 2.5-8.9) months after a diagnosis of dysplasia. Their median age was 52 (interquartile range 43-59) years. An initial diagnosis of indeterminate dysplasia was not associated with CRC [0/23; 17.7 (8.1-29.6) months]. Thirty-six patients who had an initial diagnosis of dysplasia progressed from indeterminate to low-grade dysplasia [24.2 (11.0-30.4) months]. Low-grade dysplasia was associated with a 2% (1/56; T2N0M0) risk of CRC when present in random surveillance biopsies and a 3% (2/61; T1N0M0, T4N0M0) risk if detected in endoscopically visible lesions [7.4 (5.2-33.3) months]. Eighteen patients progressed from indeterminate to high-grade dysplasia [19.1 (9.2-133.9) months]. Seventeen patients progressed from low to high-grade dysplasia [11.0 (5.8-30.1) months]. None of the patients with high-grade dysplasia (0/35) progressed to CRC [4.5 (1.7-9.9) months].

Dysplasia was associated with a low incidence of node negative CRC if surgery was deferred for up to 5 years. These findings may help inform the decision-making process for asymptomatic patients who are having to decide between intensive surveillance or surgery for UC-associated dysplasia.

Gastrointestinal luminal endoscopy is of paramount importance for diagnosis, monitoring and dysplasia surveillance in patients with both, Crohn's disease and ulcerative colitis. Moreover, with the recent recognition that mucosal healing is directly linked to the clinical outcome of patients with inflammatory bowel disorders, a growing demand exists for the precise, timely and detailed endoscopic assessment of superficial mucosal layer. Further, the novel field of molecular imaging has tremendously expanded the clinical utility and applications of modern endoscopy, now encompassing not only diagnosis, surveillance, and treatment but also the prediction of individual therapeutic responses. Within this review, we describe how novel endoscopic approaches and advanced endoscopic imaging methods such as high definition and high magnification endoscopy, dye-based and dye-less chromoendoscopy, confocal laser endomicroscopy, endocytoscopy and molecular imaging now allow for the precise and ultrastructural assessment of mucosal inflammation and describe the potential of these techniques for dysplasia detection.

Histopathology can be used to detect ulcerative colitis (UC) relapse, but diagnosis of the disease activity by histopathology requires multiple biopsies to be taken. Magnifying endocytoscopy provides a method for real-time ultra-magnifying imaging. It was recently reported that the endocytoscopy system score (ECSS) correlates well with the histopathology of UC. Here we evaluated the clinical usefulness of endocytoscopy for accurately monitoring UC during remission.

We performed endocytoscopy on 26 patients with UC in remission that had been diagnosed by conventional colonoscopy at our institution between January and April 2013. Endocytoscopy was performed at the area of the rectum where UC had been detected with conventional endoscopy. Biopsies were also taken from the same area and histopathology was evaluated by a single pathologist according to the Matts' grading system. The correlation between the relapse rate of UC and both the ECSS and the Matts' histopathological grade was evaluated.

The ECSS of the intestinal mucosa in UC showed a correlation with the Matts' histopathological grade (Spearman's |r| = 0.647). The patients were classified into two groups: those with an ECSS of 0-2 (Grade A, 12 cases) and those with an ECSS of 3-6 (Grade B, 10 cases). To date, three Grade B cases have relapsed and no Grade A cases have relapsed. The average post-endocytoscopy surveillance period was 446 ± 92 days.

The ECSS may be a predictive indicator for UC relapse since there was a correlation between the ECSS and the degree of inflammation as determined by histopathology.

Patients with inflammatory bowel diseases (IBD) have a high risk of colitis-associated dysplasia and cancer. It is important that careful surveillance with colonoscopy is performed for all patients with IBD and, more frequently, for those considered to be at high risk. Traditionally, flat dysplasia in ulcerative colitis has been considered to be detectable only by using random biopsy specimens of mucosa that appeared unremarkable during endoscopy. However, recent studies have shown that most of them are visible; thus, their detection as nonpolypoid colorectal neoplasms is an integral component in the prevention of colitic cancer.