Pathology of indeterminate colitis

Validation of the Padova Prognostic Score for Colitis in Predicting Long-Term Outcome After Restorative Proctocolectomy

Background

In 10%–20% of cases it is impossible to make a differential diagnosis between ulcerative colitis and Crohn's colitis. A 50% failure rate of J pouch ilea-anal anastomosis is observed in Crohn's colitis. In 2009, we created the Padua Prognostic Score for Colitis (PPSC) to predict the long-term clinical and functional outcome and quality of life of patients undergoing restorative proctocolectomy with J pouch. The aim of the present study is to establish and validate the accuracy of a prognostic score for chronic inflammatory bowel diseases (IBD).

Patient population and methods

The PPSC was created in 2009 by integrating clinical and histological information of patients undergoing RPC. It included preoperative perianal abscess or fistula, rectal sparing, terminal ileum involvement, skip lesions and histological diagnosis of indeterminate colitis or Crohn's colitis on the operative specimen. The validity of this score was tested in predicting postoperative abscess or fistula, anal canal disease, pouchitis, pouch failure and new diagnosis of Crohn's disease. Correlation analysis, ROC curve analysis and survival analysis were used to validate the PPSC in a different cohort from the previous one.

Results

We retrospectively enrolled in this study 138 consecutive patients undergoing CPR for ulcerative colitis (n = 127) or indeterminate colitis (n = 11) in our institution since 2005 to 2020. In this period, we observed 11 patients with postoperative abscess or fistula, 3 with anal canal disease, 40 with pouchitis, 6 with pouch failure and 6 with new diagnosis of Crohn's disease. In the new validation cohort, the PPSC confirmed to have a good accuracy in predicting the onset of postoperative CD (AUC = 74.5%, p = 0.018). Kaplan Meier curves demonstrate how a PPSC over 1 can reliably predicts the long-term onset of, pouchitis (p = 0.002) and anal abscess or fistulae (p = 0.04).

Conclusions

In this validation study we confirmed the accuracy of the PPSC in predicting postoperative fistulas or abscesses and pouchitis. Therefore, we believe that in clinical practice patients with a PPSC score greater than 1 should be warned of this risk of possible Crohn’s disease diagnosis and pouch failure.

ECCO Topical Review on Clinicopathological Spectrum and Differential Diagnosis of Inflammatory Bowel Disease

INTRODUCTION

Many diseases can imitate inflammatory bowel disease [IBD] clinically and pathologically. This review outlines the differential diagnosis of IBD and discusses morphological pointers and ancillary techniques that assist with the distinction between IBD and its mimics.

METHODS

European Crohn's and Colitis Organisation [ECCO] Topical Reviews are the result of an expert consensus. For this review, ECCO announced an open call to its members and formed three working groups [WGs] to study clinical aspects, pathological considerations, and the value of ancillary techniques. All WGs performed a systematic literature search.

RESULTS

Each WG produced a draft text and drew up provisional Current Practice Position [CPP] statements that highlighted the most important conclusions. Discussions and a preliminary voting round took place, with subsequent revision of CPP statements and text and a further meeting to agree on final statements.

CONCLUSIONS

Clinicians and pathologists encounter a wide variety of mimics of IBD, including infection, drug-induced disease, vascular disorders, diverticular disease, diversion proctocolitis, radiation damage, and immune disorders. Reliable distinction requires a multidisciplinary approach.

Is ulcerative colitis a disease of a dysfunctional microbiota?

Using the gross pathology literature and the prior decoupling of Crohn's disease from inflammatory bowel disease, IDI's White Paper puts into question the current understanding of what ulcerative colitis is and how it can be therapeutically addressed. The pathology literature, when coupled with the ability of fecal enema therapy to achieve a remission rate significantly superior to those documented for biologics, puts focus on the dominant role of the gastrointestinal microbiota in both disease induction and its recovery. The concept of endogenous enterotoxogenesis is introduced.

A contemporary and critical appraisal of 'indeterminate colitis'

Distinguishing ulcerative colitis (UC) from Crohn's disease (CD) is normally based on evaluation of a variety of clinical, radiologic, serologic and pathologic findings, the latter in biopsy and/or resection specimens. Unfortunately, some patients with IBD show overlapping pathologic features of UC and CD, which makes definite distinction between these two disorders difficult or even impossible. In most instances of uncertainty, the patient shows clinical and pathologic features of UC, but in addition, the patient's colon resection specimen reveals one or more CD-like features. In this setting, a diagnosis of indeterminate colitis (IC) is often rendered. IC is not a distinct disease entity, and, thus, it has no diagnostic criteria. The most common causes of uncertainty in IBD pathology that may lead to a diagnosis of IC in a colon resection specimen includes the presence of fulminant (severe and toxic) colitis, insufficient radiologic, endoscopic, or pathologic information (including analysis of prior biopsies) on the patient, failure to utilize major diagnostic criteria as hard evidence in favor of CD, failure to recognize unusual variants of UC and CD that may mimic each other, failure to recognize non-IBD mimics and other superimposed diseases that cause unusual pathologic features in a resection specimen, an attempt to distinguish UC from CD in mucosal biopsies of the colon and ileum, or an attempt to change the patients diagnosis (of UC or CD) based on pouch or diversion-related complications. Details of each of these causes of uncertainty are discussed, in detail, in this review article. A diagnosis of IC should never be made clinically or by pathologists based on evaluation of pre-resection colonic mucosal biopsies. Ultimately, the majority of indeterminate cases represent UC, and, thus, most of these patient can be treated safely with a colectomy combined with an ileal pouch anal anastomosis procedure.

Fibrosis in ulcerative colitis: mechanisms, features, and consequences of a neglected problem

Chronic intestinal inflammation and impaired tissue repair leading to intestinal fibrosis are a commonly observed complication in inflammatory bowel disease. This is particularly true for small bowel Crohn's disease. However, the development of fibrosis in ulcerative colitis has remained largely unexplored. This is surprising, given knowledge about its prevalence for decades, well described histopathologic features of fibrotic and stricturing ulcerative colitis, the relevance of the extracellular matrix for intestinal inflammation and fibrosis, and the clinical impact of fibrosis on stricture formation, motility, and the necessary discrimination from colonic malignancy. This systematic review summarizes the current knowledge of ulcerative colitis-related fibrosis, including epidemiology, basic mechanisms, histopathology, and clinical implications.

Focally enhanced gastritis in newly diagnosed pediatric inflammatory bowel disease

Although the significance of focally enhanced gastritis (FEG) as a marker of Crohn disease (CD) in adults has been contested, several studies suggest that it may be more specific of CD in pediatric patients. This study describes the detailed histologic features of FEG in pediatric inflammatory bowel disease (IBD) and clarifies its association with CD. A series of 119 consecutive newly diagnosed IBD patients (62 CD cases, 57 ulcerative colitis [UC] cases) with upper and lower gastrointestinal biopsies were evaluated. The histology of the gastric biopsies was reviewed blinded to final diagnoses and compared with age-matched healthy controls (n=66). FEG was present in 43% of IBD patients (CD 55% vs. UC 30%, P=0.0092) and in 5% of controls. Among CD patients, FEG was more common in younger patients (73% in children aged 10 y and below, 43% in children above 10 y of age, P=0.0358), with the peak in the 5- to 10-year age group (80%). The total number of glands involved in each FEG focus was higher in UC (6.4±5.1 glands) than in CD (4.0±3.0 glands, P=0.0409). Amongst the CD cohort, patients with FEG were more likely than those without FEG to have active ileitis (79% vs. 40%, P=0.0128) and granulomas elsewhere in the gastrointestinal tract (82% vs. 43%, P=0.0016). There was no correlation between FEG and other gastrointestinal findings of UC. We demonstrate that differences in FEG seen in pediatric CD and UC relate to not only their frequencies but also the morphology and relationship with other gastrointestinal lesions. Further, FEG is associated with disease activity and the presence of granulomas in pediatric CD.

Ulcerative colitis or Crohn's disease? Pitfalls and problems

The interpretation of colorectal biopsies taken for the initial diagnosis of chronic idiopathic inflammatory bowel disease (IBD) is challenging. Subclassification of IBD as ulcerative colitis (UC) or Crohn's disease, which may be particularly difficult, is the subject of this review. Biopsies taken at first presentation are emphasised, partly because their features have not been modified by time or treatment. Aspects of longstanding disease and of resections are also mentioned. The first part of the review comprises background considerations and a summary of histological features that are discriminant, according to published evidence, between UC and Crohn's disease in initial biopsies. Pitfalls and problems associated with making the distinction between UC and Crohn's disease are then discussed. These include: mimics of IBD; inadequate clinical details; unreliable microscopic features; absence of histological changes in early IBD; discontinuity in UC; cryptolytic granulomas; differences between paediatric and adult UC; reliance on ileal and oesophagogastroduodenal histology; and atypical features in IBD resections. Avoidance by pathologists of known pitfalls should increase the likelihood of accurate and confident subclassification of IBD, which is important for optimum medical and surgical management.

Colorectal normal histology and histopathologic findings in patients with chronic diarrhea

Collagenous and lymphocytic colitis are common causes of chronic watery diarrhea that are characterized by distinct histopathologic abnormalities without endoscopically visible lesions and are summarized as microscopic colitis. Several variants of microscopic colitis have been described, although their clinical significance still has to be defined. Preserved mucosal architecture is a histologic hallmark of microscopic colitis and distinguishes the disease from inflammatory bowel disease (IBD). In addition to architectural abnormalities, the diagnosis of IBD rests on characteristic inflammatory changes. Differential diagnosis of IBD mainly includes prolonged infection and diverticular disease-associated colitis, also known as segmental colitis associated with diverticulosis.

Inflammatory bowel disease developing in paediatric and adult age

BACKGROUND AND OBJECTIVE

In recent decades, there has been a significant increase in the incidence of inflammatory bowel disease (IBD). It has yet to be established whether the manifestations of IBD are similar in paediatric and adult ages. The objective of this study was to compare the phenotypic expression of the disease between patients with childhood-onset IBD and adulthood-onset cases, all afferent to the same clinical centre.

PATIENTS AND METHODS

Descriptive and multivariate analyses were completed on retrospective and prospective data of paediatric-onset and adult-onset consecutive cases who were diagnosed and followed at the same tertiary referral hospital of the University of Padua, Italy, during a period of 14 years (1994-2008). Paediatric-onset patients were further divided into age brackets (0-5, 6-12, and 13-17 year-olds). Analyses were conducted using the SAS package, version 9.1 (SAS Institute Inc, Cary, NC).

RESULTS

Three hundred twelve patients were analysed. At disease onset, the manifestations which were more frequent among the 133 paediatric patients (50.4% with diagnosis of Crohn disease [CD], 43.6% with ulcerative colitis, and 6% with unclassified IBD) with respect to the adult-onset patients were perianal disease (12.8%) (P < 0.0001) and extraintestinal manifestations (14.3%) (P = 0.043). Among the 179 adult patients (55.3% with diagnosis of ulcerative colitis, 36.3% with CD, and 8.3% with unclassified IBD) instead, severe abdominal pain (P = 0.008), diarrhoea (P = 0.005), and anorexia (P < 0.0001) were more frequently observed. During the follow-up, the presence of extraintestinal manifestations (50.4%) (P = 0.005) and perianal disease (44.8% of the patients with childhood-onset CD) (P = 0.006) was observed more often in the paediatric-onset group.

CONCLUSIONS

In our cases, the phenotypic expression of IBD developing in paediatric age differs from that seen in adults.

Frequency of indeterminate colitis in children and adults with IBD - a metaanalysis

BACKGROUND

Indeterminate colitis (IC) remains an enigmatic inflammatory bowel disease (IBD) phenotype. It is currently not clear whether it constitutes merely a problem of terminology, classification, or possibly an early stage of IBD distinct from Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

We analysed epidemiological data of studies comparing IC, UC and CD. We selected 14 studies investigating paediatric patients (10 prospective and 4 retrospective) and 18 studies investigating adult IBD patients (11 prospective and 7 retrospective) for this analysis.

RESULTS

Compared to adults (n=15,776) the frequency of IC is higher in children (n=6262) (children 12.7% versus adults 6.0%, p<0.0001). This difference between children and adults has been detected irrespective whether prospective or retrospective studies were selected. In both, children and adults IC was more frequent in prospective studies compared to retrospective studies (children p=0.0004; adults p=0.0024).

CONCLUSIONS

IC has been detected in a substantial proportion of paediatric patients with IBD. IC is more frequently found in children compared to adults. Further studies are required to clarify whether IC represents an IBD phenotype associated with childhood disease onset or whether the high IC frequency is due to difficulties in establishing a UC or CD diagnosis.

Restorative proctocolectomy for inflammatory bowel disease: the Padova prognostic score for colitis in predicting long-term outcome and quality of life

BACKGROUND

In 10-20% of cases, it is impossible to distinguish between ulcerative colitis and Crohn's colitis, affecting the possibility to predict the long-term outcome after restorative proctocolectomy (RPC). The study aimed to assess the accuracy of a new prognostic score for inflammatory bowel diseases (IBD) colitis [the Padova Prognostic Score for Colitis (PPSC)] in predicting long-term clinical/functional outcome and quality of life after RPC.

MATERIALS AND METHODS

The PPSC was created by the integration of histological and clinical information. The accuracy of the PPSC was tested in predicting long-term clinical outcome (i.e. pouch complications/survival) and quality of life of 58 consecutive patients who had undergone RPC in our institute from 1984 to 2004. Clinical outcome was assessed with an ad hoc functional questionnaire and the revision of the hospital and outpatients clinic notes. Quality of life surveys were carried out with the Padova IBD Quality of Life (PIBDQL) and with Cleveland Global Quality of Life (CGQL) scores.

RESULTS

The PPSC predicted pouch fistulae (accuracy = 84.5%; sensitivity = 50%; specificity = 90%) and changes in sexual life (accuracy = 71%; sensitivity = 23%; specificity = 87%). The PPSC also predicted the PIBDQL score with an accuracy of 62%, a sensitivity of 28% and a specificity of 97%, whilst it predicted the CGQL score with an accuracy of 29%, a sensitivity of 12% and a specificity of 80%. The PPSC failed to predict pouchitis or pouch failure.

CONCLUSIONS

The Padova Prognostic Score for Colitis proved effective in predicting pouch fistulae or abscesses, but not pouchitis and pouch failure. The PPSC was accurate in predicting disease-specific quality of life.

Inflammatory bowel disease in African American children compared with other racial/ethnic groups in a multicenter registry

BACKGROUND & AIMS

Few epidemiologic investigations characterize inflammatory bowel disease (IBD) in non-Caucasian children. Our study compared IBD characteristics between African Americans and non-African Americans enrolled in a multicenter pediatric IBD registry with endoscopic- and pathology-based diagnosis.

METHODS

The study retrieved data entered from January 2000 to October 2003 on children 1 to 17 years old, inclusive, followed by a consortium of academic and community US pediatric gastroenterology practices. Analyses examined racial/ethnic differences by comparing the proportions of African Americans and non-African Americans in the following categories: each diagnostic disease classification (any IBD, Crohn's disease, ulcerative colitis, indeterminate colitis); age group (<6 y, 6-12 y, or >12 y) at diagnosis or symptom onset; presence of extraintestinal manifestations, Z-scores for height and weight, immunomodulatory therapy, anatomic disease location, and abnormal hemoglobin, albumin, or sedimentation rate at diagnosis.

RESULTS

A total of 1406 patients had complete data, 138 (10%) of whom were African American. African Americans more often were older than 12 years of age at diagnosis (52% vs 37%; odds ratio [OR], 1.82; 95% confidence interval [95% CI], 1.28-2.59) and symptom onset (46% vs 30%; OR, 1.99; 95% CI, 1.40-2.84); had Crohn's disease (78% vs 59%; OR, 2.36; 95% CI, 1.56-3.58); and had a low hemoglobin level at diagnosis (39% vs 17%; OR, 3.15; 95% CI, 1.92-5.17).

CONCLUSIONS

IBD in African American children and adolescents presents more commonly with Crohn's disease and at older ages compared with non-African Americans. Racial/ethnic differences in the epidemiology of IBD, particularly Crohn's disease, among American youths require further investigation.

Indeterminate colitis: a review of the concept--what's in a name?

The precise diagnosis of colitis cannot always be established with the available diagnostic tools. The subgroup of patients with an uncertain diagnosis has been classified as "indeterminate colitis" (IC). The definition of "indeterminate," however, has changed over the years. Originally, IC was proposed by pathologists for colectomy specimens, usually from patients operated on for severe colitis, showing overlapping features of ulcerative colitis (UC) and Crohn's disease (CD). Later, the same terminology was used for patients showing no clear clinical, endoscopic, histologic, and other features allowing a diagnosis of either UC or CD. Therefore, it is difficult to compare different studies. An International Organization of Inflammatory Bowel Diseases (IOIBD) working party confirmed 1) the ambiguous nature of the term, and 2) proposes an updated classification for the category of patients with an unclear diagnosis. According to this, the term IBD unclassified (IBDU) is confirmed, as suggested by the Montreal Working Party 2005 for patients with clinically chronic colitis, that clearly have IBD but when definitive features of CD or UC are absent. In resected specimens the term "colitis of uncertain type or etiology" (CUTE) is preferred. It is accepted that most of the time this may have a prefix, such as severe, chronic. The classification of IBD varies when based only on biopsies rather than on a colectomy specimen. The vast majority of these have severe colitis. For those that cannot bear to abandon the highly ambiguous term IC, if it is used at all, this is where it can be used parenthetically.

Indeterminate colitis: definition, diagnosis, implications and a plea for nosological sanity

In 1978, Price introduced the concept of indeterminate colitis to describe cases in which colonic resections had been undertaken for chronic inflammatory bowel disease (CIBD), but a definitive diagnosis of either of the classical types of CIBD, ulcerative colitis and Crohn's disease, was not possible. This was especially apposite in cases of acute fulminant disease of the colorectum. More recently, the term indeterminate colitis has been applied to biopsy material, when it has not been possible to differentiate between ulcerative colitis and Crohn's disease. In our opinion, and in those of other workers in this field, the term should be restricted to that originally suggested by Price. This then provides a relatively well-defined group of patients in whom the implications and management of the disease are becoming much clearer. Cases where there are only biopsies with CIBD, but equivocal features for ulcerative colitis and Crohn's disease, should be termed 'CIBD, unclassified', 'equivocal/non-specific CIBD' or IBD unclassified (IBDU), in line with recent recommendations. When the diagnosis is correctly restricted to colectomy specimens, there is now good evidence that the majority of cases will behave like ulcerative colitis. Furthermore, the diagnosis should not be a contraindication to subsequent pouch surgery. When the latter is undertaken, surgeons and patients can expect an increased complication rate, compared with classical ulcerative colitis, especially of pelvic sepsis, but most patients fare well. Only very occasional patients, around 10%, will eventually be shown to have Crohn's disease. This review describes the pathology of cases appropriately classified as indeterminate colitis and the implications of that diagnosis. It also highlights recent advances in its pathological features, clinical management and its immunological and genetic associations.

Surgical approaches to cancer in patients who have inflammatory bowel disease

IBD clearly increases the risk for GI malignancies, especially CRC. The absolute number of patients that develops such malignancies is low compared with the overall cancer rate; however, younger age of onset, higher relative risk, unique clinical presentations, and problems with early diagnosis make this a serious complication of IBD. With the exception of patients with comorbid complications, such as primary sclerosing cholangitis, the prognosis is no worse for CRCs that arise as the result of IBD compared with those that arise sporadically. The prognosis remains poor for small bowel adenocarcinomas in patients who have CD, primarily because of their advanced stage at detection. Diligent surveillance is essential for early detection and treatment of IBD-related CRCs in patients with unresected colons, long-standing or extensive disease, and in those who have early-onset CD, although pundits still question whether it significantly affects prognosis and survival. Better surveillance techniques for small bowel dysplasia or malignancy in patients who have CD is needed, especially given the poor prognosis of these patients when advanced cancers are detected. Depending on the presentation and disease diagnosis, patients have several surgical treatment options and can expect good outcomes for all. When the appropriate surgical technique is used in patients who have colon or rectal cancer, along with adjuvant chemotherapy when appropriate, prognosis and function is good; however, the experience of the surgeon can affect the prognosis for IBD-related GI cancers. Surgical therapy is based not only on general oncologic principles, but also on the surgery that is appropriate for the IBD diagnosis. Resection of the mesentery and lymphadenectomy should be performed according to oncologic principles. Postoperative survival for IBD-related CRC is good, and diligent surveillance and follow-up are critical to the patient's overall prognosis.

Distinct phenotype of early childhood inflammatory bowel disease

GOALS

Our goals were to answer 2 questions: (1) Is the presentation of early-onset inflammatory bowel disease (IBD) similar to typical adolescent-onset IBD? (2) Is there variability in familial aggregation in childhood IBD?

BACKGROUND

The phenotype of IBD in children under 5 years of age (early-onset) is poorly defined. Clinical and genetic studies of IBD, however, generally assume the phenotype to be homogenous throughout childhood.

STUDY

We analyzed data from 413 consecutive pediatric IBD outpatients attending our center between 1995 and 2000. Disease type, anatomic distribution, and family history were compared between children presenting before (early-onset) and after the age of five (5 to 15 y).

RESULTS

Disease presentation was predominantly colonic in early-onset IBD, most patients presenting with ulcerative colitis (UC). Isolated colonic disease was most frequent in early-onset Crohn disease (colonic 76.5%, ileocolic 24%) compared with ileocolic disease (ileocolic 45.5%, colonic 26%, ileal 19.4%, proximal 6.3%) in the older age group. First-degree family history was highest in early-onset UC 26% versus 11% in the older UC group.

CONCLUSIONS

We describe a distinct phenotype of early childhood onset IBD, with a strikingly high familial aggregation in UC and greater tendency to present with colonic disease. As more genetic heterogeneity is identified in IBD, careful definition of phenotype is required to identify further susceptibility genes. The early-onset form of UC presents an ideal group for further genetic analysis. These phenotype differences also suggest that treatment and outcome may vary in early-onset childhood IBD; prospective studies are required to confirm this.

Anti-Saccharomyces cerevisiae antibodies are associated with the development of postoperative fistulas following ileal pouch-anal anastomosis

Although serologic testing for perinuclear antineutrophil cytoplasmic antibodies (pANCA) and anti-Saccharomyces cerevisiae antibodies (ASCA) is reportedly useful in distinguishing ulcerative colitis (UC) from Crohn's disease (CD), there are few and conflicting reports assessing their utility in predicting postoperative complications after ileal pouch-anal anastomosis (IPAA). We examined the associations between postoperative complications such as pouchitis or fistulas and pANCA and ASCA antibodies in a group of patients who underwent IPAA for UC. We conducted a retrospective chart review of 34 patients initially diagnosed with UC (four of these patients had a diagnosis of indeterminate colitis) who underwent IPAA by a single surgeon, and who had pANCA and ASCA antibody levels measured during their clinical course. Study patients were assigned to four groups based on the pattern of antibody reactivity: pANCA+/ASCA- (16 patients), pANCA-/ASCA+ (nine patients), pANCA+/ASCA+ (five patients), and pANCA-/ASCA- (four patients). The median length of follow-up was 16 months (3-144 months). None of the patients (0 of 16) who were pANCA+/ASCA- had their preoperative diagnosis of UC changed after a median follow-up of 14 months (3-118 months). Of the nine patients with a preoperative diagnosis of UC who were pANCA-/ASCA+, four patients (44%) had their diagnosis changed postoperatively to CD based on clinical findings, with a median follow-up: 15 months (5-98 months). Of 16 patients who underwent IPAA and who were pANCA+/ASCA-, 15 of 16 (93.75%), were free of fistulas postoperatively, with a median follow-up of 14 months (3-118 months). Of nine patients with a preoperative diagnosis of UC who underwent IPAA and who were pANCA-/ASCA+, four of nine (44%; p = 0.04) developed fistulas postoperatively, with a median length of follow-up of 55 months (15-67 months). No relationship between serologic profiles or antibody titer levels and the development of pouchitis was identified. In a cohort of patients undergoing IPAA for UC, serologic profiles may be useful in identifying patients at risk of postoperative fistula formation. Patients who were pANCA-/ASCA+ were at increased risk for the development of fistulas postoperatively compared to patients who were pANCA+/ASCA-, and were also more likely to have their diagnosis changed postoperatively to CD. A larger study is needed to validate these observations.

Indeterminate colitis: a significant subgroup of pediatric IBD

BACKGROUND

Indeterminate colitis (IC) is a subgroup of inflammatory bowel disease (IBD) that cannot be characterized as either ulcerative colitis (UC) or Crohn's disease (CD). Our aims are to determine the prevalence of IC in our pediatric patient population and to describe its clinical presentation, natural history,and disease distribution.

METHODS

We performed a retrospective database analysis of all children diagnosed with IBD at the Johns Hopkins Children's IBD Center between 1996 and 2001. Patient demographics, including age, sex, and age at disease onset, were tallied. Disease distribution was identified on the basis of a review of all endoscopic, colonoscopic, histopathological, and radiological records. All of the patients were followed up clinically to determine the extent of disease progression on the basis of the initial diagnosis of IC.

RESULTS

Among 250 children registered in the database, 127 (50.8%) had a diagnosis of CD, 49 (19.6%) had UC, and 74(29.6%) had IC. Patients with IC had a significantly younger mean +/- SEM age (9.53 +/- 4.8 years) at diagnosis compared with patients with CD (12.4 +/- 3.8 years; P < 0.001) but not compared with patients with UC (7.41 +/- 3.5 years). Among the patients with IC, 59 (79.7%) had a pancolitis at diagnosis, and the remaining 15 had left-sided disease that progressed to a pancolitis within a mean of 6 years. Twenty-five patients (33.7%) with an initial diagnosis of IC were reclassified to either CD or UC after a median follow-up of 1.9 years (range 0.6-4.5 years). Forty-nine patients (66.2%) maintained their diagnosis of IC after a mean follow-up of 7 years (SEM 2.5 years).

CONCLUSIONS

IC is a distinct pediatric subgroup of IBD with a prevalence that is higher than that observed in adults. Children with IC have an early age of disease onset and a disease that rapidly progresses to pancolitis. Longitudinal studies are needed to determine the clinical implications of this pediatric IBD subgroup.

Diagnostic difficulties in inflammatory bowel disease pathology

This review summarizes some of the common diagnostic problems encountered by pathologists when evaluating patients with chronic colitis and in whom inflammatory bowel disease (IBD) is either suspected or within the differential diagnosis. Both ulcerative colitis (UC) and Crohn's disease (CD) show characteristic, but non-specific, pathological features that may overlap and result in a diagnosis of 'indeterminate colitis' (IC). However, other reasons why pathologists may entertain a diagnosis of IC include failure to recognize or accept certain 'hardcore' histological features as indicative of CD, an attempt to classify cases of chronic colitis based on mucosal biopsy material or in the absence of adequate clinical and radiographic information, and the presence of other disease processes that mask, or mimic, IBD. In addition, some cases of UC may show unusual CD-like features, such as discontinuous or patchy disease, ileal inflammation, extracolonic inflammation, granulomatous inflammation in response to ruptured crypts, aphthous ulcers, or transmural inflammation. Furthermore, other forms of colitis, such as microscopic colitis, diverticulitis and diversion colitis may, on occasion, also show IBD-like changes. The clinical and pathological features that aid in the distinction between these entities, and others, are covered in detail in this review.

Pathologic features and clinical significance of "backwash" ileitis in ulcerative colitis

Patients with ulcerative colitis (UC) may develop inflammation in the distal ileum thought to be due to "backwash" of cecal contents ("backwash ileitis"). However, a systematic analysis of ileal changes in UC has never been performed, and the prevalence and criteria for "backwash" ileitis have not been defined. The aim of this study was to evaluate the prevalence and spectrum of inflammatory changes in the ileum in patients with UC and to correlate ileal changes with outcome after total proctocolectomy and ileal pouch-anal anastomosis. Routinely processed ileocolonic resection specimens from 200 consecutive patients with clinically and pathologically confirmed UC were evaluated for a wide variety of pathologic features in the ileum and colon. The ileal data were correlated with both the clinical features and the pathologic findings in the colon. Follow-up data were obtained to confirm absence of Crohn's disease and to evaluate outcome of ileo-anal pouches. Overall, 34 of 200 (17%) UC patients had inflammatory changes in the ileum (male/female ratio, 16/18; mean age, 42 years); 32 of 34 (94%) had pancolitis, which was significantly higher than the rate of pancolitis (39%) in patients without ileal disease (N = 166) (P < 0.001), but there were no other differences between patients with or without ileal pathology. In the colon, 22 of 34 (65%) patients had severe activity. Ileal changes included villous atrophy and crypt regeneration without increased inflammation (N = 3), increased neutrophilic and mononuclear inflammation in the lamina propria (N = 6), patchy cryptitis and crypt abscesses (N = 21) and focal superficial surface erosions (N = 4), some with pyloric metaplasia (N = 2 of 4). In general, the severity of ileal changes paralleled the severity of colonic activity. However, 2 of 4 (50%) patients with superficial erosions in the ileum had subtotal or left-sided colitis only, and had only mild colonic activity. Other cases showed only mild to moderate colonic activity and patchy or discontinuous involvement of the distal ileum. Upon follow-up of patients with erosions (mean, 48.5 months; range, 26-102 months), none developed manifestations of Crohn's disease anywhere in the gastrointestinal tract. The presence of inflammatory changes in the ileum had no effect on the prevalence of pouch complications or on the occurrence of dysplasia or cancer. Ileal changes in UC are not uncommon (prevalence, 17%), are generally mild in nature (villous atrophy, increased inflammation, scattered crypt abscesses), and are not associated with an increased rate of ileo-anal pouch complications, dysplasia, or carcinoma. In some cases, our findings are consistent with a backwash etiology. However, rarely, ileal erosions may occur in patients without cecal involvement, which may indicate that other pathogenetic mechanisms should be considered in the etiology of ileitis in UC patients.

Risk factors for diseases of ileal pouch-anal anastomosis after restorative proctocolectomy for ulcerative colitis

BACKGROUND & AIMS

Although pouchitis is considered the most common adverse sequela of ileal pouch-anal anastomosis (IPAA), inflammatory and noninflammatory conditions other than pouchitis are increasingly being recognized. The risk factors for these non-pouchitis conditions, including Crohn's disease (CD) of the pouch, cuffitis, and irritable pouch syndrome (IPS), have not been studied. The aim of this study was to assess risk factors for inflammatory and noninflammatory diseases of IPAA in a tertiary care setting.

METHODS

The study consisted of 240 consecutive patients who were classified as having healthy pouches (N = 49), pouchitis (N = 61), CD of the pouch (N = 39), cuffitis (N = 41), or IPS (N =50). Demographic and clinical features were assessed to determine risk factors for each of these conditions by using logistic regression analysis.

RESULTS

Risk factors remaining in the final logistic regression models were for pouchitis: IPAA indication for dysplasia (odds ratio [OR], 3.89; 95% confidence interval [CI], 1.69-8.98), never having smoked (OR, 5.09; 95% CI, 1.01-25.69), no use of anti-anxiety agents (OR, 5.19; 95% CI, 1.45-18.59), or use of NSAIDs (OR, 3.24; 95% CI, 1.71-6.13); for CD of the pouch: a long duration of IPAA (OR, 1.20; 95% CI, 1.12-1.30) and current smoking (OR, 4.77; 95% CI, 1.39-16.25); for cuffitis: arthralgias (OR, 4.13; 95% CI, 1.91-8.94) and younger age (OR, 1.16; 95% CI, 1.01-1.33); and for IPS: use of antidepressants (OR, 4.17, 95% CI, 1.95-8.92) or anti-anxiety agents (OR, 3.21; 95% CI, 1.34-7.47).

CONCLUSIONS

The majority of risk factors for the 4 inflammatory and noninflammatory conditions of IPAA are different, suggesting that each of these diseases has a different etiology and pathogenesis. The identification and modification of these risk factors might help patients and clinicians to make a preoperative decision for IPAA, reduce IPAA-related morbidity, and improve response to treatment.