The differentiation of true adenomas from colitis-associated dysplasia in ulcerative colitis: a comparative immunohistochemical study

Influence of SCENIC recommendations on terminology used for histopathologic diagnosis of inflammatory bowel disease-associated dysplasia

BACKGROUND

Published in 2015, the International Consensus Recommendations on Surveillance for Colorectal Endoscopic Neoplasia Detection and Management in Inflammatory Bowel Disease Patients (SCENIC) recommended abandoning the use of diagnostic term “dysplasia-associated lesion or mass (DALM)” for polypoid dysplastic lesions detected in patients with inflammatory bowel disease (IBD). The aim of this study was to investigate whether this recommendation had any influence on diagnostic terminologies used by pathologists in their practice.

METHODS

We retrospectively reviewed all pathology reports for surveillance colonoscopic biopsies from ulcerative colitis (UC) patients in our institution during 1/2012-12/2014 (pre-SCENIC) and 1/2016-12/2018 (post-SCENIC). These included 1203 biopsies from 901 UC patients during the pre-SCENIC period and 1273 biopsies from 977 UC patients during the post-SCENIC period. Their corresponding endoscopic findings and histopathologic diagnoses were recorded. Clinical indications for total colectomy for UC patients and corresponding histopathologic findings in colectomy specimens were also recorded and compared.

RESULTS

A total of 347 and 419 polyps/polypoid lesions were identified during the pre-SCENIC and post-SCENIC periods, among which 60 and 104 were dysplastic/ adenomatous, respectively. More polypoid dysplastic lesions were simply diagnosed as “adenoma” during the post-SCENIC period in comparison with the pre-SCENIC period (97.1% vs 65.0%; P < 0.001). The number of cases with a comment in pathology reports regarding the distinction between DALM and sporadic adenoma was also significantly decreased during the post-SCENIC period (5.8% vs 38.3%; P < 0.001). In addition, the term “dysplasia” was more consistently used for random biopsies during the post-SCENIC period. Furthermore, the terms “sessile serrated adenoma/polyp” (SSA/P) and “serrated epithelial change” (SEC) were more consistently used for polypoid lesions and random biopsies, respectively, during the post-SCENIC period, although these were not specifically addressed in the SCENIC recommendations. The indications for colectomy remained unchanged, however, despite the standardization of diagnostic terminologies.

CONCLUSION

The SCENIC recommendations relieve pathologists from the burden of distinguishing DALM from sporadic adenoma in IBD patients, which helps the standardization of diagnostic terminologies used by pathologists. The consistent use of the diagnostic terminologies may help reduce potential confusions to clinicians and patients.

The long-term incidence of dysplasia and colorectal cancer in a Crohn's colitis population-based cohort

AIM

The risk of developing colorectal cancer (CRC) in Crohn's disease (CD) has been variably reported. Chronic inflammation is associated with an increased risk of neoplasia; variable outcomes in CD possibly reflect the heterogeneous nature of the disease. The aim of this work was to characterize the risk of CRC in a New Zealand population-based cohort of CD patients with colonic inflammation.

METHOD

A review of all participants with CD in the population-based Canterbury Inflammatory Bowel Disease Study was conducted. Data on demographics, endoscopic surveillance, presence of dysplasia/neoplasia and oncological outcome were extracted. The age-adjusted standardized incidence ratio (SIR) was used to compare the incidence of CRC in the cohort with the incidence of CRC in the New Zealand population in 2006.

RESULTS

Data on 649 patients with CD were collected. Four hundred and thirty-six participants (58% female) with ileocolonic or colonic CD were included for analysis. CRC was diagnosed in 13 patients (62% female). The median age at CRC diagnosis was 58.5 years, and the mean duration of CD prior to diagnosis of CRC was 20.4 years. When compared with the New Zealand population (using census data), the overall age-adjusted SIR was 4.1 (95% CI 2.4-7.1).

CONCLUSION

This population-based cohort of patients with colonic CD shows a significantly increased risk of CRC compared with the general population. This is consistent with the colonic location of inflammation increasing the risk of neoplasia. Inclusion of patients with isolated upper gastrointestinal/ileal CD in similar studies may mask the truly increased risk for patients with long-standing colonic inflammation.

Sporadic adenoma or ulcerative colitis associated neoplasia? The endoscopist's information has an impact on diagnosis and patient management

BACKGROUND

Diagnosing low grade intraepithelial neoplasia (LGIN) in patients with ulcerative colitis (UC) is difficult. Distinguishing between sporadic adenoma (SA) and UC associated LGIN is even more challenging but has clinical impact. We aimed to examine, if the morphological distinction between both entities is reliably possible, how it influences patient's outcome and the role of the endoscopist in this decision with respect to current endoscopy classification schemes.

METHODS

Seven pathologists retrospectively reevaluated 425 cases of LGIN in UC patients, diagnosed between 2009 and 2017 with preceding expert consensus and follow up in two separate readings, based on published morphological differentiation criteria. In the first evaluation, the observers were blinded to any clinical data. In the second evaluation, they knew patients' age as well as endoscopic features. They also rated their subjective diagnostic certainty.

RESULTS

Diagnostic correctness improved significantly in the second assessment as did the pathologists' confidence in their diagnoses (p < 0.001 - p = 0.019). Knowledge of clinical and endoscopical data led to a higher percentage of SA (71.8% vs. 85.6%). UC associated LGIN showed significant earlier LGIN relapse as well as more high grade intraepithelial neoplasia and carcinoma during follow up (p < 0.001, p < 0.001, p = 0.005).

CONCLUSIONS

Distinction between SA and UC associated LGIN is important as it has an impact on patients' follow up and treatment. Morphological distinction remains difficult with moderate interobserver variability. Adequate clinical information significantly improves pathologists' diagnoses as well as their confidence in their diagnoses.

Revisiting the distinct histomorphologic features of inflammatory bowel disease-associated neoplastic precursor lesions in the SCENIC and post-DALM Era

Distinct histomorphologic features of colitis-associated dysplasia (CAD) or neoplastic precursors in inflammatory bowel disease (IBD) have never been clearly identified. In this study, we tried to further explore the differentiating morphologic features of CAD by retrospectively reviewing the lesions that were clearly associated with carcinomas (carcinoma-related lesions) and by comparing between endoscopically nonpolypoid (non-adenoma-like) lesions and polypoid (adenoma-like) lesions and sporadic conventional adenomas found in the noncolitic mucosa and in patients without IBD. Our study results have revealed that (1) precursor lesions related to IBD-associated colorectal carcinomas were almost always nonpolypoid in macroscopic/endoscopic appearance; (2) nearly half of the carcinoma-related lesions and nonpolypoid lesions were similarly nonadenomatous (nonconventional) lesions, largely serrated type, with no or only mild/focal adenomatous dysplasia, and commonly had mixed adenomatous and nonadenomatous features; (3) carcinoma-related and nonpolypoid adenomatous dysplastic lesions frequently showed some peculiar histocytologic features that we observed and described for the first time, including mixed features of inflammatory pseudopolyps or granulation tissue, pleomorphic and disarrayed nuclei, micropapillary or hobnailing surface epithelial cells, and microvesicular or bubbling cytoplasm of dysplastic cells; and (4) polypoid lesions in the colitic mucosa were identical to sporadic adenomas in the noninflamed mucosa and in patients without IBD, and they lacked the aforementioned features. The seemingly distinctive morphologic characteristics that we proposed here, although still not absolutely specific or unique, can be used as the features of inclusion for identifying CAD on endoscopic biopsies when the endoscopy images are not readily available to pathologists and thus to alert clinicians for a closer follow-up.

DALM, rest in peace: a pathologist's perspective on dysplasia in inflammatory bowel disease in the post-DALM era

There are few abbreviations in surgical pathology that are associated with as much immediate recognition, frustration, and confusion as DALM (dysplasia-associated lesion or mass). DALM is used to describe endoscopically visible dysplastic lesions in the surveillance of patients with inflammatory bowel disease. However, the diagnosis of DALM has been complicated by the inconsistent criteria and use of terminology for describing dysplasia in inflammatory bowel disease, and a tendency to relate DALM with the need for colectomy. Fortunately, advancements in both endoscopic visualization and local excision capability have allowed for a more defined management of dysplasia in inflammatory bowel disease. In 2015, the Surveillance for Colorectal Endoscopic Neoplasia Detection and Management in Inflammatory Bowel Disease Patients International Consensus Recommendations (SCENIC) Development Panel, a panel of predominantly expert gastroenterologists and endoscopists in surveillance of inflammatory bowel disease, published a consensus statement. One recommendation was to abandon DALM-related terminology in favor of endoscopic descriptors modified from the Paris endoscopic classification. Recommendations on surveillance and management of dysplastic lesions were also provided. Nevertheless, interval carcinomas and metachronous neoplasia remain persistent issues. This review aims to provide an update on the post-DALM terminology and management recommendations for inflammatory bowel disease-associated dysplasia necessary for a meaningful communication between pathologists and clinicians.

Cancer risk after resection of polypoid dysplasia in patients with longstanding ulcerative colitis: a meta-analysis

BACKGROUND & AIMS

American and European guidelines propose complete endoscopic resection of polypoid dysplasia (adenomas or adenoma-like masses) in patients with longstanding colitis, with close endoscopic follow-up. The incidence of cancer after detection of flat low-grade dysplasia or dysplasia-associated lesion or mass is estimated at 14 cases/1000 years of patient follow-up. However, the risk for polypoid dysplasia has not been determined with precision. We investigated the risk of cancer after endoscopic resection of polypoid dysplasia in patients with ulcerative colitis.

METHODS

MEDLINE, EMBASE, PubMed, and the Cochrane library were searched for studies of patients with colitis and resected polypoid dysplasia, with reports of colonoscopic follow-up and data on cancers detected. Outcomes from included articles were pooled to provide a single combined estimate of outcomes by using Poisson regression.

RESULTS

Of 425 articles retrieved, we analyzed data from 10 studies, comprising 376 patients with colitis and polypoid dysplasia with a combined 1704 years of follow-up. A mean of 2.8 colonoscopies were performed for each patient after the index procedure (range, 0-15 colonoscopies). The pooled incidence of cancer was 5.3 cases (95% confidence interval, 2.7-10.1 cases)/1000 years of patient follow-up. There was no evidence of heterogeneity or publication bias. The pooled rate of any dysplasia was 65 cases (95% confidence interval, 54-78 cases)/1000 patient years.

CONCLUSION

Patients with colitis have a low risk of colorectal cancer after resection of polypoid dysplasia; these findings support the current strategy of resection and surveillance. However, these patients have a 10-fold greater risk of developing any dysplasia than colorectal cancer and should undergo close endoscopic follow-up.

Gastrointestinal dysplasia

The term dysplasia (intraepithelial neoplasia) is used to refer to neoplastic but non-invasive epithelium. Dysplasia in the gastrointestinal tract is considered a carcinoma precursor and a marker of high cancer risk for the site at which it is found. It is diagnosed by pathologists using a set of cytological and architectural features. There are many pitfalls in the diagnosis of gastrointestinal dysplasia. One reason for difficulty in dysplasia diagnosis is the significant heterogeneity in the appearances of each grade of dysplasia. In addition, the features that characterise dysplasia are only subtly different from those of regenerating epithelium, particularly at the low end of the spectrum, making this distinction difficult. For these reasons, and because of significant implications of this diagnosis for patient care, the interpretations of biopsies taken for dysplasia surveillance are considered challenging by most pathologists. In this article, we review definition, classification, and histological features and grading of gastrointestinal dysplasia with focus on Barrett's oesophagus (BE) related dysplasia, gastric epithelial dysplasia (GED) and dysplasia arising in the background of inflammatory bowel disease (IBD). We also discuss observer variability and the role of adjunctive markers in dysplasia diagnosis, and limitation with regard to surveillance of patients with BE and IBD due to sampling error.

Surgical procedure for sporadic colorectal cancer in patients with mild ulcerative colitis

Restorative proctocolectomy is recognized as the standard procedure for colitic cancer in patients with ulcerative colitis (UC). However, whether this represents the optimal procedure for UC patients with sporadic cancer remains questionable, as functional quality of life differs substantially between patients with proctocolectomy and partial resection. This study considered possible problems associated with sporadic cancer in UC. Case 1 is a 55-year-old man with a 3-year history of UC who was treated with endoscopic resection for sporadic adenocarcinoma in the rectum. Low anterior resection was subsequently performed due to deep invasion. The final diagnosis was pT3. Differentiating between histopathological diagnoses of sporadic and colitic cancer was difficult. Case 2 is a 71-year-old woman with a 6-year history of UC who was diagnosed with type 1 sporadic sigmoid colon cancer. Dementia and umbilical hernia were present as complications. Total colectomy was performed in consideration of the coexisting complications. Although partial resection for sporadic cancer could be favorable in mild colitis, further immunosuppressive treatments have the potential to elevate the risk of recurrence for advanced cancer. Restorative proctocolectomy may be safer to avoid further recurrent colitis and cancer except in elderly patients or those with other complications.

Cancer risk in IBD: How to diagnose and how to manage DALM and ALM

The risk of developing neoplasia leading to colorectal cancer is significantly increased in ulcerative colitis (UC) and most likely in Crohn’s disease. Several endoscopic surveillance strategies have been implemented to identify these lesions. The main issue is that colitis-associated neoplasms often occurs in flat mucosa, often being detected on taking random biopsies rather than by identification of these lesions via endoscopic imaging. The standard diagnostic procedure in long lasting UC is to take four biopsies every 10 cm. Image enhancement methods, such as chromoendoscopy and virtual histology using endomicroscopy, have greatly improved neoplasia detection rates and may contribute to reduced random biopsies by taking targeted “smart” biopsies. Chromoendoscopy may effectively be performed by experienced endoscopists for routine screening of UC patients. By contrast, endomicroscopy is often only available in selected specialized endoscopic centers. Importantly, advanced endoscopic imaging has the potential to increase the detection rate of neoplasia whereas the interplay between endoscopic experience and interpretation of histological biopsy evaluation allows the physician to make a proper diagnosis and to find the appropriate therapeutic approach. Colitis-associated intraepithelial neoplasms may occur in flat mucosa of endoscopically normal appearance or may arise as dysplasia-associated lesion or mass (DALM), which may be indistinguishable from sporadic adenomas in healthy or non-colitis mucosa [adenoma-like mass (ALM)]. The aim of this review was to summarize endoscopic and histological characteristics of DALM and ALM in the context of therapeutic procedures.

Expression of p53, VEGF, microvessel density, and cyclin-D1 in noncancerous tissue of inflammatory bowel disease

We aimed to evaluate the carcinogenesis risk in inflammatory bowel disease via p53 mutation and its relation with hyperproliferation (cyclin-D1) and angiogenesis (with vascular endothelial growth factor [VEGF] and microvessel density) and whether these events play important roles in pathogenesis of inflammatory bowel disease. Colonic tissue samples of 26 ulcerative colitis, 6 Crohn's disease, and 8 amoebic colitis patients as well as samples of 10 healthy controls were stained with p53, cyclin-D1, CD34, and VEGF monoclonal antibodies by immunohistochemistry and evaluated semiquantitatively. Expression of p53 was higher in ulcerative colitis than in the healthy control and amoebic colitis groups (4.15 +/- 2.07, 1.4 +/- 1.5, 1.3 +/- 1.5; P < 0.001). The Crohn's disease group had the highest p53 expression (4.6 +/- 1.6). The Crohn's disease, ulcerative colitis, and amoebic colitis groups all had higher VEGF expression than did the healthy controls (respectively, 4.3 +/- 1.2, 2.92 +/- 2.0, 2.3 +/- 1.5, 0.6 +/- 0.97; P < 0.001). Also, microvessel density was statistically higher in all three colitis groups than in healthy controls. Cyclin-D1 expression in all four groups was similar. The study showed that p53 mutation was present in nonneoplastic mucosa of inflammatory bowel disease patients. Detecting strong p53 overexpression with VEGF overexpression may help in differentiating inflammatory bowel disease from other colitis.

Pathology of dysplasia and cancer in inflammatory bowel disease

Morphologic identification of dysplasia in mucosal biopsies is the best and most reliable marker of an increased risk for malignancy in patients who have inflammatory bowel disease, and it forms the basis of the recommended endoscopic surveillance strategies that are in practice for patients who have this illness. In ulcerative colitis (UC) and Crohn's disease (CD), dysplasia is defined as unequivocal neoplastic epithelium that is confined to the basement membrane, without invasion into the lamina propria. Unfortunately, unlike in UC, only a few studies have evaluated the pathologic features and biologic characteristics of dysplasia and carcinoma in CD specifically. As a result, this article focuses mainly on the pathologic features, adjunctive diagnostic methods, and differential diagnosis of dysplasia in UC.

Mechanisms of acupuncture and moxibustion in regulation of epithelial cell apoptosis in rat ulcerative colitis

AIM: To investigate the effect of acupuncture and moxibustion on epithelial cell apoptosis and expression of Bcl-2, Bax, fas and FasL proteins in rat ulcerative colitis.

METHODS: A rat model of ulcerative colitis was estabelished by immunological methods and local stimulation. All rats were randomly divided into model control group (MC), electro-acupuncture group (EA), herbs-partition moxibustion group (HPM). Normal rats were used as normal control group (NC). Epithelial cell apoptosis and expression of Bcl-2, Bax, fas and FasL proteins were detected by TUNEL and immunohistochemiscal method respectively.

RESULTS: The number of epithelial cell apoptosis in MC was significantly higher than that in NC, and was markedly decreased after the treatment with herbs-partition moxibustion or electro-acupuncture. The expression of Bcl-2, Bax, fas and FasL in colonic epithelial cells in MC was higher than that in NC, and was markedly down- regulated by herbs-partition moxibustion or electro-acupuncture treatment.

CONCLUSION: The pathogenesis of ulcerative colitis in rats involves abnormality of apoptosis. Acupuncture and moxibustion can regulate the expression of Bcl-2, Bax, fas and FasL proteins and inhibit the apoptosis of epithelial cells of ulcerative colitis in rats by Bcl-2/Bax, fas/FasL pathways.

The histologic diagnosis of dysplasia, dysplasia-associated lesion or mass, and adenoma: a pathologist's perspective

Patients with ulcerative colitis are at an increased risk of developing dysplasia and carcinoma. The histologic recognition of dysplasia arising in this setting, particularly when patients have active colitis, can be challenging. However, even if it is clear that the patient has dysplasia, further challenges include the distinction of low-grade dysplasia from high-grade dysplasia and the distinction of an inflammatory bowel disease-related dysplastic lesion from a sporadic adenoma. This review article will summarize some of these issues from the gastrointestinal pathologist's perspective.

[Sporadic adenoma and colitis-associated intraepithelial neoplasia: a difficult differential diagnosis]

The differential diagnosis between sporadic adenoma and colitis-associated neoplasia is difficult. Clinical, histological and molecular genetic methods are available to recognise a difference between these two entities. The aim of the present analysis was to check known criteria in a large series of patients and 352 patients with ulcerative colitis and concomitant intraepithelial neoplastic lesions [149 adenomas (A), 123 colitis-associated intraepithelial neoplasias (N), 80 carcinomas (K)] were investigated. Clinical history helped to identify patients with sporadic adenoma since patients with colitis-associated neoplastic lesions presented with different data such as age (A: 61.3+/-13 years, N: 48.4+/-16.4 years, K: 53.9+/-16.9 years), duration of disease (A: 6.9+/-8.1 years, N: 11.9+/-10 years, K: 13.6+/-9.6 years), frequency of pancolitis (A: 28.6%, N: 56.3%, K: 48.3%) and frequency of solitary lesions (A: 83.7%, N: 23.1%, K: 51.9%). The differential diagnosis between adenoma and colitis-associated neoplasia in patients with ulcerative colitis appears to be possible but the diagnosis should only be made in the remission phase. Furthermore the patients need a careful endoscopic and bioptic follow-up. If in doubt one should consider colitis-associated neoplasia especially when there are multiple intraepithelial neoplastic lesions. Long-term follow-up studies are urgently needed.

Artificial neural networks distinguish among subtypes of neoplastic colorectal lesions

BACKGROUND & AIMS

There is a subtle distinction between sporadic colorectal adenomas and cancers (SAC) and inflammatory bowel disease (IBD)-associated dysplasias and cancers. However, this distinction is clinically important because sporadic adenomas are usually managed by polypectomy alone, whereas IBD-related high-grade dysplasias mandate subtotal colectomy. The current study evaluated the ability of artificial neural networks (ANNs) based on complementary DNA (cDNA) microarray data to discriminate between these 2 types of colorectal lesions.

METHODS

We hybridized cDNA microarrays, each containing 8064 cDNA clones, to RNAs derived from 39 colorectal neoplastic specimens. Hierarchical clustering was performed, and an ANN was constructed and trained on a set of 5 IBD-related dysplasia or cancer (IBDNs) and 22 SACs.

RESULTS

Hierarchical clustering based on all 8064 clones failed to correctly categorize the SACs and IBDNs. However, the ANN correctly diagnosed 12 of 12 blinded samples in a test set (3 IBDNs and 9 SACs). Furthermore, using an iterative process based on the computer programs GeneFinder, Cluster, and MATLAB, we reduced the number of clones used for diagnosis from 8064 to 97. Even with this reduced clone set, the ANN retained its capacity for correct diagnosis. Moreover, cluster analysis performed with these 97 clones now separated the 2 types of lesions.

CONCLUSIONS

Our results suggest that ANNs have the potential to discriminate among subtly different clinical entities, such as IBDNs and SACs, as well as to identify gene subsets having the power to make these diagnostic distinctions.

Colorectal neoplasia in ulcerative colitis-recent advances

It is recognized that ulcerative colitis (UC) predisposes to the development of colorectal adenocarcinoma (CRC), and the molecular pathway for this process differs from that for sporadic CRCs. However, several important details regarding the risk factors for and the molecular changes underlying UC-related colorectal carcinogenesis have only come to light lately. First, recent data suggest environmental factors related to long-standing inflammation contribute more to this increased cancer risk than an inherited susceptibility. Second, molecular changes that may represent the first steps in the development of neoplasia are being increasingly identified in non-dysplastic, colitic mucosa. Third, there is now good evidence suggesting that UC-related CRC may develop along more than one molecular pathway. These emerging data will hopefully contribute to attempts to prevent the development of UC-related CRC, e.g. through refining surveillance programmes. Details of the molecular heterogeneity of UC-related dysplasia and CRC may also help develop reliable tools for diagnosing the former and for predicting the behaviour of the latter. Finally, there is increasing awareness of non-epithelial colorectal malignancies which are associated with UC and may potentially increase in incidence with changes in the medical management of this inflammatory disease.

The pathology of epithelial pre-malignancy of the gastrointestinal tract

This chapter deals with pre-malignant epithelial lesions of the gastrointestinal tract that have the potential to become cancers. Pre-malignant lesions are divided into two types: those characterized by dysplastic mucosa and those without dysplasia. Examples of the two types are present in the oesophagus, stomach and intestine. In the oesophagus, dysplasia of the squamous epithelium is a precursor to squamous carcinoma. There are differences in interpretation between Western and Japanese pathologists in the diagnosis of oesophageal squamous lesions. Dysplasia in Barrett's oesophagus is regarded as a precursor of adenocarcinoma. The goal of endoscopic surveillance in Barrett's mucosa is the detection of high-grade dysplasia. There are several problems with our current knowledge of high-grade dysplasia and controversies regarding its management. There are differences in the interpretation of biopsies of gastric epithelial dysplasia between Japanese and Western pathologists. In the colon, pre-malignant lesions include dysplasia seen in inflammatory bowel disease and colonic adenomas. The most significant predictor of the risk of malignancy in patients with inflammatory bowel disease is the presence of dysplasia in colonic biopsies. Because of the similarity of neoplasia throughout the gastrointestinal tract, there have been attempts to unify its classification, terminology and diagnostic criteria internationally, the most recently proposed modified classification of gastrointestinal neoplasia being the Vienna classification. Dysplasia of the columnar mucosa has a similar appearance in Barrett's oesophagus, the stomach and the colon. Criteria for its histological diagnosis and grading are reviewed, with an emphasis on areas of diagnostic difficulty such as interobserver variation, and discrepancies between Western and Japanese pathologists. Implication of the presence of dysplasia that are specific to each organ site are discussed, highlighting weaknesses and controversies in current knowledge.

Clinical features of inflammatory bowel disease

The purpose of this review is to highlight new developments during the past year regarding diagnosis and clinical features of inflammatory bowel disease. Endoscopy remains the cornerstone for diagnosis and evaluation of ileocolonic inflammatory bowel disease. In ulcerative colitis, recent studies have challenged the concept of a continuous and homogeneous inflammatory process with constant rectal involvement: patchy inflammation and rectal sparing were reported in treated ulcerative colitis, and frequent cecum and appendiceal orifice skip lesions were confirmed. Cross-sectional imaging techniques usefully complement endoscopy by assessing whole-bowel thickness and detecting abscesses and fistulae. Furthermore, echo Doppler ultrasound is able to measure mesenteric blood flow, which is increased in active inflammatory bowel disease and seems to parallel inflammatory disease activity. Osteopenia, which affects approximately half of patients with inflammatory bowel disease, can be detected by dual-energy x-ray absorptiometry and prevented. Hyperhomocysteinemia, a predisposing factor for thrombosis, seems to be more frequent in inflammatory bowel disease, and can be corrected by folate supplementation. The concept of an aggressive, penetrating form of Crohn disease with early postoperative recurrence as opposed to a more indolent, nonpenetrating form of the disease, with later recurrence, was recently challenged. The most significant predictor of the risk of malignancy in inflammatory bowel disease remains the presence of dysplasia in colonic biopsy specimens. A dysplastic polypoid lesion or mass is a strong predictor of cancer but should be distinguished from the dysplasia inherent in a coincident sporadic adenoma.