Mucosal biopsy of the rectum, colon, and distal ileum

Sampling and Reporting of Inflammatory Bowel Disease

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

Effects of Ustekinumab on Histologic Disease Activity in Patients With Crohn's Disease

BACKGROUND & AIMS

Although ustekinumab is an effective therapy for moderate to severe Crohn's disease (CD), its effects on the microscopic manifestations of CD are unknown.

METHODS

We evaluated the effects of ustekinumab on histologic CD activity in an analysis of data from 251 participants in phase 3 induction and maintenance studies. Two endoscopic biopsy samples were collected at weeks 0, 8, and 44 from the ileum, splenic flexure, and rectum (18 biopsy samples from each patient). Histologic activity was assessed based on global histology activity scores (GHASs).

RESULTS

At week 8, the mean GHAS was significantly reduced after ustekinumab induction treatment (from 10.4 ± 7.0 to 7.1 ± 5.9; P < .001) but not in patients who received placebo (from 9.2 ± 6.4 to 7.8 ± 6.2). At week 44 in the randomized maintenance therapy population, the mean GHAS remained reduced from week 8 in patients who received subcutaneous ustekinumab (90 mg every 8 weeks; from 7.4 ± 7.7 to 6.1 ± 4.7) but not every 12 weeks (from 5.3 ± 3.9 to 8.7 ± 4.1) or placebo (from 9.2 ± 3.8 to 10.9 ± 7.1). In the pooled (randomized and nonrandomized) maintenance therapy population, histologic improvement continued in patients given ustekinumab every 8 weeks (from 7.1 ± 6.2 to 5.2 ± 4.2; P < .0001) but not in those given ustekinumab every 12 weeks (from 6.1 ± 5.7 to 7.2 ± 5.1) or placebo (from 8.2 ± 4.2 to 8.9 ± 6.8). A significantly greater proportion of patients achieved histologic response (≥50% decrease in GHAS from baseline) at week 44 if they received ustekinumab every 8 weeks (50% in the randomized maintenance population and 54% in the pooled maintenance population) compared with every 12 weeks (17% and 39% in the randomized and pooled populations, respectively) or placebo (0% and 22% in the randomized and pooled populations, respectively) (P = .0137 for every 8 weeks vs placebo and P = .3529 for every 12 weeks vs placebo in the randomized population; P = .0168 for every 8 weeks vs placebo and P = .3069 for every 12 weeks vs placebo in the pooled population). Regional and overall mean GHASs correlated with the simple endoscopic score for CD (r = .6255, P < .0001). Multivariate analysis found an association between histologic improvement and endoscopic or histologic burden at baseline.

CONCLUSIONS

In an analysis of data from participants in phase 3 induction and maintenance trials, we found histologic improvement in a greater proportion of patients given ustekinumab vs placebo. The largest improvements occurred in patients who received ustekinumab maintenance therapy every 8 weeks. ClinicalTrials.gov nos. NCT01369329, NCT01369342, and NCT01369355.

Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE): Determining Therapeutic Goals for Treat-to-Target

OBJECTIVES

The Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE) program was initiated by the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD). It examined potential treatment targets for inflammatory bowel disease (IBD) to be used for a "treat-to-target" clinical management strategy using an evidence-based expert consensus process.

METHODS

A Steering Committee of 28 IBD specialists developed recommendations based on a systematic literature review and expert opinion. Consensus was gained if ≥75% of participants scored the recommendation as 7-10 on a 10-point rating scale (where 10=agree completely).

RESULTS

The group agreed upon 12 recommendations for ulcerative colitis (UC) and Crohn's disease (CD). The agreed target for UC was clinical/patient-reported outcome (PRO) remission (defined as resolution of rectal bleeding and diarrhea/altered bowel habit) and endoscopic remission (defined as a Mayo endoscopic subscore of 0-1). Histological remission was considered as an adjunctive goal. Clinical/PRO remission was also agreed upon as a target for CD and defined as resolution of abdominal pain and diarrhea/altered bowel habit; and endoscopic remission, defined as resolution of ulceration at ileocolonoscopy, or resolution of findings of inflammation on cross-sectional imaging in patients who cannot be adequately assessed with ileocolonoscopy. Biomarker remission (normal C-reactive protein (CRP) and calprotectin) was considered as an adjunctive target.

CONCLUSIONS

Evidence- and consensus-based recommendations for selecting the goals for treat-to-target strategies in patients with IBD are made available. Prospective studies are needed to determine how these targets will change disease course and patients' quality of life.

Systematic review: histological remission in inflammatory bowel disease. Is 'complete' remission the new treatment paradigm? An IOIBD initiative

BACKGROUND AND AIMS

Advances in the medical management of inflammatory bowel disease (IBD) have altered treatment targets. Endoscopic mucosal healing is associated with better outcomes in IBD, though less is known about the significance of achieving histological remission. Our aim was to perform a systematic review to investigate whether histological or 'complete' remission constitutes a further therapeutic target in IBD.

METHODS

A bibliographic search was performed on the 1st of October 2013 and subsequently on the 1st of March 2014 of online databases (OVID SP MEDLINE, OVID EMBASE, National Pubmed Central Medline, Cochrane Library, ISI, conference abstracts), using MeSH terms and key words: ("inflammatory bowel diseases" OR "crohn disease" OR "ulcerative colitis" OR "colitis") AND ("mucosal healing" OR "histological healing" OR "pathological healing" OR "histological scoring" OR "pathological scoring").

RESULTS

The search returned 2951 articles. 120 articles were cited in the final analysis. There is no validated definition of histological remission in IBD. There are 22 different histological scoring systems for IBD, none of which are fully validated. Microscopic inflammation persists in 16-100% of cases of endoscopically quiescent disease. There is evidence that histological remission may predict risk of complications in ulcerative colitis beyond endoscopic mucosal healing, though data are scarce in Crohn's disease.

CONCLUSIONS

Histological remission in IBD represents a target distinct from endoscopic mucosal healing, not yet routinely sought in clinical trials or practice. There remains a need for a standardized and validated histological scoring system and to confirm the prognostic value of histological remission as a treatment target in IBD.

European consensus on the histopathology of inflammatory bowel disease

The histologic examination of endoscopic biopsies or resection specimens remains a key step in the work-up of affected inflammatory bowel disease (IBD) patients and can be used for diagnosis and differential diagnosis, particularly in the differentiation of UC from CD and other non-IBD related colitides. The introduction of new treatment strategies in inflammatory bowel disease (IBD) interfering with the patients' immune system may result in mucosal healing, making the pathologists aware of the impact of treatment upon diagnostic features. The European Crohn's and Colitis Organisation (ECCO) and the European Society of Pathology (ESP) jointly elaborated a consensus to establish standards for histopathology diagnosis in IBD. The consensus endeavors to address: (i) procedures required for a proper diagnosis, (ii) features which can be used for the analysis of endoscopic biopsies, (iii) features which can be used for the analysis of surgical samples, (iv) criteria for diagnosis and differential diagnosis, and (v) special situations including those inherent to therapy. Questions that were addressed include: how many features should be present for a firm diagnosis? What is the role of histology in patient management, including search for dysplasia? Which features if any, can be used for assessment of disease activity? The statements and general recommendations of this consensus are based on the highest level of evidence available, but significant gaps remain in certain areas.

Evaluating the association between histological manifestations of cord colitis syndrome with GVHD

Cord colitis syndrome (CCS) is a recently proposed clinical entity characterized by a persistent diarrheal illness after cord blood transplantation (CBT), which is not caused by GVHD or CMV colitis. CCS is histologically characterized by chronic active colitis with granulomatous inflammation and Paneth cell metaplasia suggesting chronicity. However, the specificity of these pathological features to CCS remains to be validated. We conducted a retrospective study of 49 patients who had diarrhea and underwent diagnostic colonoscopy with biopsy following allogeneic hematopoietic SCT. None of the patients met the clinical criteria for CCS. Chronic active colitis with granulomatous inflammation and Paneth cell metaplasia was present in 12/33 (36%) patients with biopsy-proven GVHD, 4/6 (67%) patients with CMV colitis and 2/15 (13%) patients with nonspecific colitis. In patients with GVHD and/or CMV colitis, these pathological features were present in 4/8 (50%) patients after CBT and in 11/26 (42%) patients undergoing BMT or PBSCT. These results demonstrate that chronic active colitis with granuloma and Paneth cell metaplasia is not only a specific feature of CCS but also is present in GVHD and CMV colitis, irrespective of stem cell source.

Macrophage-related diseases of the gut: a pathologist's perspective

The resident macrophages of the gastrointestinal tract represent the largest population of macrophages in the human body and are usually located in the subepithelial lamina propria. This strategic location guarantees a first-line defense to the huge numbers of potentially harmful bacteria and antigenic stimuli that are present in the intestinal lumen. In non-inflamed mucosa, macrophages phagocytose and kill microbes in the absence of an inflammatory response. However, in the event of an epithelial breach and/or microbial invasion, new circulating monocytes and lymphocytes will be recruited to the damaged area of the gut, which will result in the secretion of proinflammatory mediators and engage a protective inflammatory response. Although macrophages are usually not conspicuous in normal mucosal samples of the gut, they can easily be detected when they accumulate exogenous particulate material or endogenous substances or when they become very numerous. These events will mostly occur in pathologic conditions, and this review presents an overview of the diseases which are either mediated by or affecting the resident macrophages of the gut.

Expression patterns of angiopoietin-1, -2, and tie-2 receptor in ulcerative colitis support involvement of the angiopoietin/tie pathway in the progression of ulcerative colitis

The active stage of ulcerative colitis (UC) involves transmigration of polymorphonuclear (PMN) cells to colonic epithelia. The angiopoietin (Ang) pathway plays a role as the regulator of PMN transmigration. To clarify the role of the Ang/Tie pathway in the activation of UC, especially in cypt abscess formation, 67 tissue samples were obtained from patients with UC and ten controls without UC for immunohistochemical analysis for the expression of Ang-1, -2, or Tie-2. The epithelia of crypt abscess was strongly positive for Ang-1 and -2 for all 57 samples derived from patients with active UC, though the colorectal epithelium without crypt abscess showed minimal expression of Ang-1, -2, and Tie-2. Numerous transepithelial migrating PMN cells in crypt abscesses also expressed Tie-2. The specimens of UC patients in remission showed significantly less immunoreactivity for Ang-1, -2, or Tie-2. These findings suggest that the Ang/Tie pathway may play a role in the progression of UC.

The clinical significance of focal enhanced gastritis in adults with isolated ileitis of the terminal ileum

BACKGROUND

Isolated chronic ileitis in the terminal ileum, without accompanying chronic colitis, is not an uncommon finding present in biopsy specimens from patients being evaluated for chronic diarrhea. Among the many entities that should be included in the differential diagnosis are Crohn's disease and nonsteroidal antiinflammatory drugs (NSAIDs)-induced enterocolitis. In high-prevalence Crohn's disease populations, focal enhanced or active gastritis (FEG) may be a good predictor of Crohn's disease; however, this criterion may not apply in a general clinical setting. Our goal was to determine if FEG is a pathological marker of Crohn's disease in patients with isolated chronic ileitis in the terminal ileum.

METHODS

We examined 46 consecutive cases of isolated chronic ileitis with concurrent stomach biopsies. These patients did not have evidence or previous history of inflammatory bowel disease. The diagnostic criteria of chronic ileitis included crypt distortion and inflammation, plasmacytosis in the lamina propria, ulceration, and/or pyloric gland metaplasia.

RESULTS

Of the 46 cases reviewed, 25 (54%) cases were diagnosed with Crohn's disease later, confirmed by clinical manifestations and/or biopsies with a follow-up of up to 4 years. The stomach biopsies of these patients were either normal or demonstrated a spectrum of histological findings, including FEG, chronic gastritis with or without Helicobacter pylori organisms, chemical gastropathy, and normal tissues. FEG was more commonly present in Crohn's disease patients (36%) than in non-Crohn's disease patients (5%) (P < 0.01).

CONCLUSIONS

The presence of FEG is a good indicator for the diagnosis of Crohn's disease in adult patients with isolated chronic ileitis.

Colorectal carcinoma with dome-like phenotype: an under-recognised subset of colorectal carcinoma?

BACKGROUND

The term dome carcinoma has been applied to a variant of colorectal carcinoma, thought to derive from M-cells of the gut-associated lymphoid tissue. Its distinguishing morphological features include a non-polypoid plaque-like lesion composed of closely apposed cystically dilated glands lined by a single layer of non-mucinous cells, intensely PAS-positive intraluminal material, and a close spatial relation to lymphoid stroma.

AIMS AND METHODS

A search in the literature for such cases and the authors' experience with carcinomas sharing morphological details with dome carcinoma are presented to direct focus on this unique phenotype of colorectal carcinoma and to expand on its morphology.

RESULTS

Four such examples, all stage pT1, pN0 have been previously reported. Here two additional cases, with several features of dome carcinoma, stage pT1 and pT2, respectively, are added. An extensive intramucosal component, unassociated with adenomatous growth, a pink quality of the lesional cells, low grade budding, absence of cytoplasmic pseudofragments, and absence of necrosis characterised the present cases as well as intact MMR-proteins and loss of APC. As opposed to two of the previously reported cases, intraepithelial lymphocytes were unapparent in these cases and the lymphoid stroma was effaced along with tumour progression in one of the present cases. Hence, a range of appearances is encompassed by the dome carcinoma. The uncommon reporting of dome carcinoma may be due to lack of awareness of this particular subset of colorectal carcinoma. Indeed, one of the current cases was signed out as a conventional carcinoma, despite the comment in the pathology report of an unusual morphology.

CONCLUSION

Dome carcinoma may be more under-recognised than rare. The reporting of variants of colorectal carcinoma, displaying histological features suggestive of dome carcinoma, is encouraged in order to obtain more exact knowledge on its putative clinical significance.

Pathology of inflammatory bowel disease

Inflammatory bowel disease in childhood refers to ulcerative colitis, Crohn's disease, and colitis of an indeterminate type. Their gross and microscopic features are discussed along with the differential diagnosis from other childhood conditions associated with bloody diarrhea.

Colonic Paneth cell metaplasia is pre-neoplastic condition of colonic cancer or not?

Background

The carcinogenesis of colorectal cancer has been accepted by a model for a cascade of genetic alterations, named the adenoma-carcinoma sequence. In order to elucidate the carcinogenesis of the colorectal cancer more clearly, the genetic abnormalies of the non-neoplastic mucosal epithelium of the colon and rectum should be investigated. It has been speculated that colonic Paneth cell metaplasia (PaM) is one of the pre-neoplastic mucosa of colonic cancer. Therefore, we studied the propria mucosa of the right colon with PaM from the standpoints of the frequency of the K-ras codon 12 mutations (K-ras), which is initial genetic abnormality in colorectal cancer, and the loss of heterozygosity of microsatellite markers (LOH-MS), which has a relationship to development of colorectal cancer.

Methods

Fifty-two regions with PaM histopathologically from 12 surgically resected right colon specimens were studied. DNA extraction of the colonic mucosa with PaM was obtained using a microdissection method, and the frequency of the K-ras of PaM was investigated by enriched polymerase chain reaction-enzyme linked mini-sequence assay, and the frequency of the LOH-MS (D2S123, D17S250 and D5S346) of PaM was examined by high resolution fluorescenced labeled PCR primers.

Results

K-ras mutation was detected in fifteen regions among 52 PaM (28.9%). All mutations were a single mutation and GGT changed to AGT in eleven and GAT in four. LOH-MS were detected in twenty-one regions among 52 PaM (40.4%) (D2S123: 35.4%, 17/48 regions, D17S250: 13.7%, 7/51 regions, and D5S346: 0%, 0/52 regions). No K-ras mutations and LOH-MS were detected in the controls (Colorectal mucosa with no PaM).

Conclusions

Colonic mucosa with Paneth cell metaplasia may be one of the pre-neoplastic mucosa in the development of the colonic epithelial neoplasia.

Observer variation of diagnoses based on simple biopsy criteria differentiating among Crohn's disease, ulcerative colitis, and other forms of colitis

BACKGROUND AND AIM

Simple mucosal biopsy criteria proposed by authors reliably differentiate idiopathic inflammatory bowel disease (IBD) from other forms of colitis (non-IBD) and Crohn's disease involving the colon (CD) from ulcerative colitis (UC). The aim of this study is to investigate the reproducibility of these criteria.

METHODS

Three established pathologists and two medical students blindly examined 20 sets of multiple biopsy slides from patients with CD, 20 from those with UC, and 20 from those with non-IBD. The students had been given instructions on histological definitions using another 15 sets previously. Each observer evaluated 10 histological items required in the criteria and determined categorical diagnoses such as definite IBD and probable UC. Interobserver agreement for the individual histological items was measured by using kappa analysis and Pearson's correlation, while it was measured for categorical diagnoses with the use of Spearman's rank correlation.

RESULTS

All of the individual histological items expressed excellent or fair-to-good agreement among the five observers, although two items associated with the criteria for CD and UC had poor agreements among the students. With regard to categorical diagnoses based on the criteria for IBD and non-IBD, and those for CD and UC, coefficients for Spearman's rank correlation exceeded 0.92 and 0.86 among the pathologists, and 0.76 and 0.74 among the students, respectively; all of the coefficients were statistically significant (P < 0.05).

CONCLUSIONS

The simple criteria were sufficiently reproducible and would help most pathologists to make an automated and objective diagnosis.

Simple mucosal biopsy criteria differentiating among Crohn disease, ulcerative colitis, and other forms of colitis: measurement of validity

BACKGROUND

Recently established mucosal biopsy criteria reliably differentiate idiopathic inflammatory bowel disease (IBD) from other forms of colitis (non-IBD), and Crohn disease involving the colon (CD) from ulcerative colitis (UC) but were inconvenient in practical use because of the need for relatively complicated calculations. Our objectives were to establish simple criteria in which calculation could be done in the user's head and to measure their validity.

METHODS

On the basis of the above original criteria, we constructed two sets of criteria in which coefficients and constants were simplified to integral numbers. The first set of criteria consisted of the diagnostic categories 'definite IBD', 'probable IBD', 'unknown', 'probable non-IBD', and 'definite non-IBD'. Similarly, the second set had five categories from 'definite CD' to 'definite UC'. The validity of the criteria was evaluated in 117 patients with CD, 125 with UC, and 484 with non-IBD.

RESULTS

In categories of probable IBD and probable non-IBD both sensitivity and specificity exceeded 96.3%. Probable CD and probable UC showed sensitivities of 95.7% and 92.0% and specificities of 93.6% and 98.3%.

CONCLUSIONS

Despite simplified coefficients and constants, the validity appeared to be high enough to apply the present criteria to routine work.

Food protein-induced enterocolitis syndrome: laboratory perspectives

The expression of food protein allergy in man is very heterogeneous, varies with the age of the subject and is to a certain extent genetically determined. Skin prick tests with standardized food extracts are a sensitive method for detection of immunoglobulin E bound to reactive cells such as mast cells. Various tests on cellular immunity have been developed, especially because T-cell mediated reactions are considered to play a role in mainly delayed gastrointestinal reactions to cow's milk proteins. Food allergy may involve the entire gut, from mouth to rectum, including the esophagus. Abnormalities in intestinal permeability are the hallmarks of the inflamed gut, and may contribute to diagnosis of food induced enteropathy. What determines the characteristics of the intestinal inflammatory response is largely the cytokine responses triggered by the pathologic mechanism, whatever its origin, in the stomach, the small intestine, and the colon. A so-called T-helper type 2 response is characteristic of the allergic subject. A secretion of tumor necrosis factor-alpha alpha by blood cells of children allergic to milk was shown. All means of investigation may help in analyzing food substitutes for allergic infants.

Colite do cólon excluso: modelo experimental em ratos

Em 1981 Glotzer et al. descreveram um tipo de proctocolite, semelhante à retocolite ulcerativa, limitado ao segmento excluído do trânsito fecal, na ausência de doença intestinal inflamatória. O presente estudo tem por finalidade avaliar as alterações ocorridas no cólon após sua exclusão do trânsito, com o fim de se estabelecer um modelo em ratos que permita estudar a doença. Utilizaram-se 35 ratos Wistar-PUCPR, machos com 120 dias de idade, divididos em 4 grupos. Sob anestesia inalatória procedeu-se à laparotomia mediana, secção transversa do cólon esquerdo e colectomia de 0,5 cm par se ter o padrão inicial (Mo). Seguiu-se o fechamento do coto distal, colostomia terminal com maturação precoce do coto proximal e laparorrafia. Realizaram-se as verificações nos seguintes tempos: grupo A após uma semana, grupo D após 2 semanas, grupo B após 4 semanas e grupo C após 8 semanas. Avaliou-se o cólon excluído macro e microscópicamente (Mf) analisando-se: a reação inflamatória, a concentração de colágeno e o comportamento das células caliciformes. Comparadas os momentos Mo e Mf registrou-se a presença de úlceras em 11 cólons (p=0,0010) não relacionadas com o tempo de exclusão. Reação inflamatória agudo-crônica ou crônica discreta esteve presente em todos os tempos. Em todos os cólons observou-se diminuição significante da espessura da parede. No Mo predominou o colágeno tipo I (p=0,008) enquanto que no Mf o predomínio foi do colágeno III (p=0,008). Foi constante a diminuição do colágeno total, a perda de colágeno I e o aumento de colágeno III. Não houve mudança significante do percentual de área ocupada por células caliciformes. Conclui-se que a exclusão do cólon distal, de até 8 semanas, no rato por colostomia determina: atrofia do cólon e o aparecimento de lesões ulceradas superficiais com reação inflamatória discreta.

Colonic epithelial lymphocytosis without a thickened subepithelial collagen table: a clinicopathologic study of 40 cases supporting a heterogeneous entity

Lymphocytic colitis (LC) is classically described as a triad of chronic nonbloody, watery diarrhea, normal or nearly normal endoscopy findings, and colonic epithelial lymphocytosis without a thickened subepithelial collagen table (SECT). It is unknown how often patients with colonic epithelial lymphocytosis without a thickened SECT actually present with this classic triad. Cases diagnosed histologically as lymphocytic or microscopic colitis were reviewed. Criteria for inclusion were the presence of at least 15 surface lymphocytes per 100 epithelial cells and the absence of a thickened SECT (<12 microm). Clinical features and course were recorded by chart review and telephone follow-up. Forty patients met the inclusion criteria, including 25 women and 15 men with a mean age of 63.2 years (range, 25-83 years). Twenty-eight patients had the classic triad and were designated as having classic LC. The other 12 patients fulfilled the histologic criteria but not the clinical or endoscopic criteria for classic LC and were classified as having atypical LC (constipation, five patients; macroscopic colitis at endoscopy, five patients; hematochezia, one patient; and incidental finding, one patient). Clinically, patients with classic LC were predominantly women and had a higher incidence of autoimmune disease (p = 0.03) than did those with atypical LC. Histologically, surface eosinophilia was significantly greater in patients with classic LC (p = 0.04). Twenty patients were using nonsteroidal antiinflammatory drugs at the time of their colonic biopsy. Surface epithelial lymphocyte counts were higher in these patients, particularly in the distal sigmoid colon (p = 0.02). Fourteen patients had associated autoimmune disease, including three patients with sprue diagnosed by small bowel biopsy, all of whom responded to gluten withdrawal. Diarrhea present in 25 patients, without documented evidence of celiac sprue, was self-limited in five, resolved with treatment in three, required intermittent treatment in eight, daily treatment in five, and was refractory to treatment in four. All eight patients who experienced spontaneous or treatment-related symptom resolution had classic LC. No histologic feature correlated with clinical course. In conclusion, our study shows that colonic epithelial lymphocytosis without a thickened SECT is a histologic finding seen in a heterogeneous group of patients. Within this heterogeneous group is a distinct subset of patients who have the classic clinicopathologic triad of LC. This subset of patients has striking similarities to patients with collagenous colitis, lending further support to a close relationship between these two entities. Atypical LC comprises a heterogeneous group and includes patients with idiopathic constipation, coexisting LC and inflammatory bowel disease, and possibly infectious colitides. Because of the clinical heterogeneity among our study population, the descriptive term colonic epithelial lymphocytosis may be a more prudent diagnosis than lymphocytic colitis in the absence of adequate clinical information.

Focal lymphocytic colitis and collagenous colitis: patterns of Crohn's colitis?

The morphologic findings in mildly active colonic Crohn's disease (CD) include crypt disarray, patchy edema, and small lymphoid aggregates with neutrophils, sometimes associated with aphthous ulcers. We describe four patients with CD whose colonic biopsies focally showed a lymphocytic colitis morphology, and one patient with CD whose biopsies showed a collagenous colitis morphology. The lymphocytic and collagenous colitis patterns of injury preceded the eventual clinical pathologic diagnosis of CD in four patients. Colonoscopic abnormalities were found in four patients. The lymphocytic colitis pattern was focal, involving some biopsy fragments, whereas other biopsy fragments were normal or had minimal nonspecific inflammation. In one patient, moderate numbers of neutrophils were admixed with the lymphoplasmacytic infiltrates. The presence of colonoscopic abnormalities, focal changes, and moderate admixed neutrophils could assist in the distinction from lymphocytic or collagenous colitis, both of which are colonoscopically normal, usually diffuse, and devoid of, or contain only a sparse number of, neutrophils. A limited number of biopsy fragments may be incorrectly interpreted as lymphocytic or collagenous colitis. The temporal relationships suggest that these morphologic patterns precede typical active CD.

Biopsy diagnosis of colitis: possibilities and pitfalls

The histopathologic diagnosis of inflammation is common in colorectal biopsies but is of limited value, if not further specified. We reviewed 280 endoscopic colorectal biopsy specimens for nonneoplastic disease from 100 consecutive patients in order to assess (a) the frequency of inflammation in excess of the physiologic infiltrate, (b) the frequency with which the cause of the inflammation could be specified, and (c) the interobserver variability in diagnosing inflammation. Based on the reviewers' impression, each case was classified into one of three categories: (I) normal or nonspecific change, (II) nonspecific inflammation, and (III) inflammation suggestive or diagnostic of specific cause. Inflammation was diagnosed in 68% of cases. The majority of these cases (75%) showed features typically associated with specific types of colitis, including Crohn's disease (n = 16), ulcerative colitis (n = 13), inflammatory bowel disease not otherwise specified (n = 5), infectious colitis (n = 6), ischemic colitis (n = 4), solitary rectal ulcer syndrome (n = 3), radiation colitis (n = 2), and lymphocytic colitis (n = 2). Interobserver variability was greatest in biopsy specimens interpreted by the reviewers as normal or showing nonspecific changes, most of which had been diagnosed as mild inflammation by the original pathologists. Etiologic classification of colitis was lacking in 59% of the cases interpreted by the reviewers as suggestive or diagnostic of a specific cause. We conclude that (a) the majority of colorectal biopsy specimens from patients with nonneoplastic disease in this series show inflammation, (b) the majority of such cases allow a specific cause of colitis to be suggested or firmly diagnosed, and (c) pathologists tend to overdiagnose the physiologic inflammatory infiltrate as evidence of colitis and underdiagnose specific etiologic types of colitis.

Morphologic criteria applicable to biopsy specimens for effective distinction of inflammatory bowel disease from other forms of colitis and of Crohn's disease from ulcerative colitis

BACKGROUND

Inflammatory bowel disease (IBD)--and Crohn's disease (CD) and ulcerative colitis (UC) in particular--could be more reliably diagnosed by using biopsy criteria incorporating the colorectal distribution of specific histologic features. The aim of this study was to elucidate criteria distinguishing IBD from other forms of colitis (non-IBD), and CD from UC on the basis of multiple colorectal biopsies.

METHODS

We examined multiple biopsy specimens (mean, 6.1) from 299 consecutive Japanese subjects with active colitis and performed multiple logistic regression analyses on 70 histologic features, from which 2 equations were constructed for the probabilities (P(IBD) and P(CD)) of a) IBD (versus non-IBD), and b) CD (versus UC), respectively, being present. On the basis of a receiver-operating characteristic curve, we determined four cut-off values for P(IBD) and constructed the criteria, consisting of the five categories 'definite IBD', 'probable IBD', 'unknown', 'probable non-IBD', and 'definite non-IBD'. The criteria for CD versus UC were constructed in a similar manner. Their validities were evaluated using 132 Canadian subjects.

RESULTS

The statistically significant histologic features were as follows: for IBD, crypt architectural abnormalities, basal plasmacytosis with severe chronic inflammation, and distal Paneth cell metaplasia; for CD, segmental crypt architectural abnormalities and mucin depletion, mucin preservation at the active sites, and focal chronic inflammation without crypt atrophy. In the categories of probable IBD and probable non-IBD, both sensitivities and specificities exceeded 97%. Probable CD and probable UC showed high specificities of more than 97%, and their sensitivities were 94% and 89%, respectively. Kappa statistics showed these criteria to be sufficiently reproducible.

CONCLUSIONS

Specific histological features together with their distribution can reliably diagnose IBD, distinguish CD from UC, and provide an estimate of the probability of the underlying disease being present.

The differential diagnosis of Crohn's disease and ulcerative colitis

Most cases of inflammatory bowel disease (IBD) can be correctly labelled as Crohn's disease (CD) or ulcerative colitis (UC) with careful initial gross and microscopic examination of biopsy and resection specimens together with close clinical and radiological correlation. Until we understand more of the aetiology and immunology of IBD we should admit that there are limitations imposed by current diagnostic criteria, consider the use of reporting proforma to improve diagnostic accuracy, and accept that in a small number of patients clinicopathological features will overlap, and CD may masquerade as UC.

Case report: endoscopic ultrasonographic findings of mucosal prolapse syndrome

A 41-year-old man with mucosal prolapse syndrome received endoscopic ultrasonography. The lesion was mildly hypoechoic and irregular, with extension into the muscularis propria and disappearance of the normal mucosal and submucosal layers. In addition, an enlargement of the muscularis propria, bridging towards the mucosal layer with merging of the two layers, was observed. These findings suggest the usefulness of endoscopic ultrasonography in the diagnosis of mucosal prolapse syndrome.

Guidelines for the initial biopsy diagnosis of suspected chronic idiopathic inflammatory bowel disease. The British Society of Gastroenterology Initiative

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Importance of cryptolytic lesions and pericryptal granulomas in inflammatory bowel disease

AIMS

To explore the diagnostic importance of pericryptal granulomas associated with epithelial lysis in colorectal biopsy specimens (cryptolytic colitis).

METHODS

A series of patients with suspected inflammatory bowel disease and colorectal biopsy specimens showing either isolated pericryptal granulomas (14 cases) or non-granulomatous pericryptal inflammation (eight cases) were followed. A diagnosis of Crohn's disease was established if subsequent biopsy specimens or intestinal resections showed unequivocal non-crypt related granulomas, or if there was evidence of significant small bowel disease.

RESULTS

Of the 14 patients with pericryptal granulomas and biopsy specimens, 10 were subsequently found to have Crohn's disease; of the eight patients with pericryptal inflammation only, one developed Crohn's disease. The former group also had a much higher instance of morbidity and required surgical intervention more often.

CONCLUSIONS

The presence of cryptolytic granulomas in a colorectal biopsy specimen otherwise showing only non-specific inflammatory changes should always raise suspicion of Crohn's disease, especially if surgery or ileo-anal pouch formation is contemplated.

Interpretation of large intestinal mucosal biopsy specimens

The development of flexible endoscopes has led to a great increase in the examination and mucosal biopsy evaluation of all portions of the large intestine and rectum. Examinations are now performed not only for the determination of diagnosis but also for the monitoring of the course of a wide variety of conditions and for the early detection of complications. This review concentrates on the uses and interpretations of such biopsies in a large number of inflammatory conditions, with special emphasis on the correlations with clinical and functional features. Illustrated are examples of infections, idiopathic inflammatory bowel disease (IBD), vascular disorders, motor and mechanical conditions, toxic and physical reactions, and other inflammatory conditions. Mucosal biopsy specimens also are obtained to identify dysplasia and to evaluate mass lesions, and these subjects are well covered in other articles within this symposium. In patients with chronic disorders multiple examinations are now expected to follow the course of the disease and to detect and correct any complications at an early stage. The exact reasons for the endoscopy and relevant clinical data are essential for the optimal analysis of these mucosal biopsy specimens.

Observer variation and discriminatory value of biopsy features in inflammatory bowel disease

If skilled histopathologists disagree over the same biopsy specimen, at least one must have an incorrect interpretation. Thus, disagreement is associated with, although not the cause of, diagnostic error. The present study aimed to determine the magnitude of variation among 10 observers with a special interest in gastrointestinal histopathology. They independently interpreted the same biopsy specimens for morphological features which may discriminate between patients with Crohn's disease and ulcerative colitis and normal subjects. Thirty of 41 features had agreement measures significantly better than expected by chance (p < 0.05). The range of agreement in the 45 observer pairs over the final diagnosis was 65-76%. There was good agreement in discriminating between normal slides and those showing confirmed inflammatory bowel disease. For normal slides, however, the term nonspecific inflammation was often applied and without any consistency. In addition, true Crohn's disease slides were often and consistently thought to be ulcerative colitis. Having identified 11 important discriminatory morphological features, two multiple regression analyses were then carried out to produce a scoring system for inflammatory bowel disease. These results suggest there is considerable room for improvement in the reliability of colonic biopsy specimen interpretation and that this could probably be achieved using more exact definitions of morphological features and diseases.

Allergic proctocolitis in infants: a prospective clinicopathologic biopsy study

Allergic proctocolitis is a major cause of rectal bleeding in infants, but its clinical features and laboratory results are often nonspecific. Our previous retrospective study demonstrated that large numbers of eosinophils in colonic mucosal biopsy specimens were highly associated with cases of allergic proctocolitis. Therefore, we prospectively examined 60 colonic mucosal biopsy specimens from the same sites (4, 8, and 12 cm from the anal verge) in 20 infants with clinically confirmed allergic proctocolitis to validate this morphologic feature, to characterize its distribution, and to correlate these data with the clinical information. The patients (age range, 4 to 304 days) were fed breast milk or a variety of formulas and all presented with rectal bleeding. Sigmoidoscopic examination was abnormal in 19 cases, typically characterized by focal areas of mucosal erythema. The major histologic finding was a strikingly focal increase in the number of eosinophils in all mucosal compartments, with a predilection to aggregate in close association with lymphoid nodules. Eosinophilic infiltration varied not only between biopsies at different sites, but also within individual biopsy specimens. Only 12 of 20 patients (60%) had all three of their biopsy specimens categorized as abnormal; in the remainder, only one (four patients) or two (four patients) of the three biopsy specimens were abnormal. The average number of eosinophils per high-power field of lamina propria for all cases was 15.6. No significant correlation was identified between the number of eosinophils in the mucosa and the patient's age, length of illness, endoscopic appearance, or type of inciting formula. In summary, eosinophils appear to be an excellent marker for infantile allergic proctocolitis. Given the focal distribution of the eosinophils, multiple mucosal biopsy specimens should be obtained and several levels of each examined to confirm the diagnosis.

Escherichia coli O157:H7-associated colitis. A clinical and histological study of 11 cases

Hemorrhagic colitis is characterized by abdominal cramps, bloody diarrhea, and no or low-grade fever. Most cases are caused by the Shiga-like toxin-producing bacteria, Escherichia coli O157:H7. Nineteen colonic biopsy specimens and one resection specimen were reviewed from 11 patients with E. coli O157:H7-associated colitis to determine whether histologic features could be useful in diagnosis or in suggesting pathogenesis. All specimens showed hemorrhage and edema in the lamina propria. Specimens from nine patients were focally necrotic and showed hemorrhage and acute inflammation in the superficial mucosa with preservation of the deep crypts, similar to the pattern of injury associated with acute ischemic colitis. Specimens from five patients showed neutrophils focally infiltrating the lamina propria and crypts, resembling the pattern of injury seen in infectious colitis. One or both of these histologic patterns were observed in specimens from all but one patient. Specimens from four patients had poorly formed inflammatory pseudomembranes. It is concluded that the histologic features of E. coli O157:H7-associated colitis resemble a combination of ischemic and infectious injuries similar to those described in toxin-mediated Clostridium difficile-associated colitis. This suggests that the toxin(s) produced by these E. coliplay a role in the colonic injury. Infection with E. coli O157:H7 should be considered in the differential diagnosis of ischemic and infectious colitis.

Diffuse excess mucosal collagen in rectal biopsies facilitates differential diagnosis of solitary rectal ulcer syndrome from other inflammatory bowel diseases

Solitary rectal ulcer syndrome (SRUS) is sufficiently uncommon that the clinician or general pathologist may lack familiarity with the disorder and may confuse it with other inflammatory bowel diseases. To evaluate the role of collagen staining in facilitating the differential diagnosis of SRUS, an initial open review was undertaken on 1672 consecutive patients whose 4780 colorectal biopsies were stained with H&E with added saffron to demonstrate collagen. Excess mucosal collagen was present in 39 (2.3%) of these patients. Twenty patients with a diffuse excess of mucosal collagen in biopsies from rectal ulcer margins or from otherwise abnormal rectal mucosa had SRUS; in the remaining 19 patients, excess mucosal collagen was focal (seven ischemic colitis, five collagenous colitis, three adenocarcinoma, and four chronic idiopathic ulcerative colitis). Diffuse excess mucosal collagen never was seen in idiopathic inflammatory bowel disease (128 Crohn's colitis and 446 ulcerative colitis). Blinded reviews then were performed on rectal biopsies from 33 patients with a variety of diagnoses (14 SRUS and 19 controls). Diffuse excess collagen by saffron staining was consistently observed in SRUS but was absent in all 19 controls. Additional blinded reviews were carried out because the collagen staining pattern in ischemic colitis, although focal, could potentially be confused with SRUS. It was possible to differentiate these two diseases blindly from one another by using additional histologic criteria (14 SRUS and 12 ischemic colitis). We conclude that the demonstration of a diffuse excess of mucosal collagen in rectal biopsies facilitates the diagnosis of SRUS and differentiates it from idiopathic ulcerative colitis and Crohn's disease, with which SRUS is often confused, and other inflammatory bowl diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

Rectum has abnormal ion transport but normal cAMP-binding proteins in cystic fibrosis

The luminal membranes of involved tissues in cystic fibrosis (CF) are relatively impermeable to Cl and the regulation of Cl transport by adenosine 3',5'-cyclic monophosphate (cAMP)-mediated hormones is abnormal. We investigated the human rectum as a putative model for CF. We compared in vivo transrectal potential difference (PD) in CF and in normal subjects in response to sequential perfusions with various test solutions. The base-line PD was different in normal (-35.5 +/- 4.0 mV; lumen negative; mean +/- SE; n = 9) and CF subjects (-23.4 +/- 3.1 mV; n = 6; P less than 0.025) and was eliminated by amiloride (10(-4) M) perfusion in both groups by 3 min. However, in response to a Cl-free solution with amiloride, all six CF subjects exhibit less of a change in PD (PD, -2.2 +/- 1.2 mV vs. -11.7 +/- 1.5 mV in 6 controls; P less than 0.01). Furthermore, normal subjects (n = 7) respond to a 5 mM theophylline + amiloride perfusion with an increase in lumen-negative PD, whereas, CF subjects (n = 6) show no increase in lumen-negative PD. Rectal biopsy specimens from four normal and four CF subjects exhibit similar (2- to 3-fold) increases in theophylline-induced cAMP content and have similar cAMP-binding proteins (CF, n = 3; control, n = 3). We conclude that the rectum is an involved epithelium in CF in which the aberration may lie at a point beyond the binding of cAMP to its protein kinase.

Pathology of inflammatory bowel disease in colorectal mucosal biopsies

The importance of colorectal biopsies in the diagnosis and management of inflammatory bowel disease (IBD) is reviewed and the histologic criteria for identifying the different types of colitis are outlined. While most of the histopathologic features of the various forms of colitis are characteristic, none is pathognomonic. Accordingly, emphasis is placed on considering all clinical and investigational data in evaluating histopathologic changes found in colorectal mucosal biopsies.

Effect of water irrigations on human colonic mucosa structure after sigmoidostomy

The colonic mucosa of patients with sigmoidostomies, who were operated on for rectal cancer, and treated thereafter for different periods of time with daily water irrigations to obtain complete evacuation, was investigated by histologic and histochemical methods. Microscopic examination of the test specimens showed that the epithelial continuity, the characteristic brush border, and the positive mucous reaction to PAS and Alcian blue-Alcian yellow methods were not significantly changed with respect to controls. In some test specimens a remarkable number of mitoses were evident in the crypts. Since this could result from water irrigation stimuli and/or might represent an early manifestation of a restored carcinogenetic process, specific investigations were performed on the 0-acylated sialic acids of the colonic mucins, which have been reported to represent markers of early malignant changes in colorectal epithelial cells. The results did not reveal alterations of the sialomucins in the treated specimens with respect to controls.

Coeliac proctitis

An increased association of ulcerative colitis and coeliac disease has been reported, as have the results of several small-bowel biopsy studies in ulcerative colitis. Forty-two patients from a population of 438 patients with coeliac disease had rectal biopsies. Fourteen of these showed inflammation of various degrees of severity, including three compatible with a diagnosis of ulcerative colitis. The presenting complaint in 34 of these patients was diarrhoea or steatorrhoea. Twenty-seven patients had coeliac disease diagnosed at the same time or after their rectal biopsy. The other 15 were previously diagnosed coeliacs. Twelve of the 14 patients with abnormal rectal biopsy specimens were known to have subtotal/total villous atrophy at the time of rectal biopsy. Proctitis as seen in these coeliac patients had no unique features to differentiate it from proctitis caused by other disorders. The diarrhoea/steatorrhoea stopped in all patients on commencement of a gluten-free diet, except in those with ulcerative colitis. Proctitis is common in patients with coeliac disease presenting with diarrhoea/steatorrhoea. This study supports the finding of an increased association of coeliac disease and ulcerative colitis and is, to our knowledge, the first rectal biopsy study of a coeliac population.

Depth of colorectal biopsies with proctoscopic forceps

It has been suggested that a barium enema may safely follow a colorectal biopsy superficial to the muscularis propria within 24 hours, but that the colon radiograph should be postponed 3 to 7 days following a biopsy including this layer. The authors prospectively studied 67 colorectal biopsies obtained with the Wolf 3-mm (grasping) and 5-mm (cutting) proctoscopic forceps from 49 patients to determine the depth of the biopsies. The 5-mm biopsies were not significantly deeper than the 3-mm biopsies (p greater than 0.5). In 18 patients biopsied with each instrument, the 3-mm biopsy was deeper in two cases (11%), the 5-mm biopsy was deeper in three cases (17%), and the biopsies were of equal depth in 13 cases (72%). None of the biopsies with either forceps reached the muscularis propria. The authors concluded that it may be unnecessary to wait longer than 24 hours before performing a barium enema after colorectal biopsy with these forceps.

Histochemistry of small intestinal dysplasia in familial polyposis coli

Biopsies of duodenal and ileal mucosa from patients with familial polyposis coli were studied. Areas of atypia were identified in the duodenum of six patients and in the ileum of three patients. Grade I atypia was characterized by crowding and elongation of cells and nuclei, a slight reduction in the number of goblet cells and the presence of a brush border; grade II atypia was further characterized by pseudo- or pluristratification of cells, a marked reduction in the number of goblet cells and the absence of a brush border. In areas of atypia, columnar cells often contained PAS-positive apical granules, which were diastase-resistant and unstained by alcian blue at any pH; the brush border, even where recognizable in haematoxylin-eosin and PAS-stained sections, was unreactive histochemically for alkaline phosphatase. Goblet cells were few in areas of atypia, but those present were regularly stained by PAS and alcian blue pH 2.6. Apical granules, similar in their histochemical characteristics to those observed in columnar cells in areas of atypia, were also found in otherwise normal mucosal areas, even in some patients with no overt areas of atypia in the biopsies studied. These granules have been interpreted as an abnormality, possibly preceding the onset of atypia. Hyperplasia of goblet cells, secreting mucins with the same staining pattern as in normal intestine, was found in some patients, either adjacent to areas of atypia or independent of them. Intervening columnar cells had a normal morphology, alkaline phosphatase-reactive brush borders and no sign of mucus secretion. This goblet cell hyperplasia has been interpreted as a reactive, nonspecific alteration of the mucosa.

Inflammatory polyposis two years after ischemic colon injury

Inflammatory polyps occur in association with ulcerative colitis, Crohn's disease, and other inflammatory diseases of the colon. The occurrence of inflammatory polyps following ischemic colitis has not been well documented. A 49-year-old man suffered complications of hypoperfusion, including renal insufficiency, hepatic failure, shock lung, and ischemic colitis following emergent repair of an acute aortic dissection. Although the renal, hepatic, and pulmonary complications resolved, the patient continued to experience intermittent bloody diarrhea more than two years after his initial presentation. Barium enema and colonoscopy revealed numerous pedunculated polyps in the descending and sigmoid colon. Histopathology of the polyps removed by snare electrocautery showed them to be inflammatory polyps. We believe these are the sequelae of chronic ischemic colitis.

Crypt production in normal and diseased human colonic epithelium

New crypts are added continuously to the adult mouse intestinal epithelium by a process of crypt replication. Branching crypts found in the epithelium represent a stage in the process of crypt replication. In "normal" human colonic epithelium we found a small but definite percentage of branching crypts, 0.44 +/- 0.16, indicating that new crypts are being produced at a low rate in this epithelium. Significantly higher (P less than .001) percentages of branching crypts, 30.4 +/- 5.75, 15.1 +/- 1.08, and 13.2 +/- 1.05, were found in diseased colonic epithelium from patients with ulcerative colitis, Crohn's disease, and multiple polyposis, respectively. These results may be interpreted as suggesting that the rate of crypt production in human colonic epithelium is increased in a number of disease states. We concluded that, as in the mouse intestinal epithelium, the rate of the crypt replication process in human colonic epithelium is plastic and may respond to a variety of conditions.

Immunohistologic demonstration of abnormal colonic crypt cell kinetics in ulcerative colitis

A monoclonal antibody, Ki-67, that reacts with cells in the proliferative phases (G1, G2, S, and M) of the cell cycle was used in an immunohistochemical labeling reaction to examine the colonic crypt epithelium in active ulcerative colitis, inactive ulcerative colitis, and normal mucosa. The proportions of labeled cells in the lower two thirds (proliferative zone) and in the upper quarter of the crypt were determined. The proportions of Ki-67-positive crypt epithelial cells in both the proliferative zone and the upper crypt were higher in biopsy specimens from patients with active ulcerative colitis than from patients with normal mucosa or with inactive ulcerative colitis. In inactive ulcerative colitis the proportion of Ki-67-positive epithelial cells in the proliferative zone of the crypt was higher than in normal mucosa. These results are similar to those obtained in studies using tritiated thymidine to determine the proportion of cells in the DNA-synthesizing thymidine to determine the proportion of cells in the DNA-synthesizing phase of the cell cycle and suggest that immuno-histochemical staining with Ki-67 may be a practical method for measuring the proliferative activity of epithelial cells in patients with ulcerative colitis and other disorders of the gastrointestinal tract.

Diagnosis of duodenal and ampullary epithelial neoplasms by endoscopic biopsy: a clinicopathologic and immunohistochemical study

A series of 19 duodenal and 16 ampullary neoplasms was studied to determine their pathologic features on endoscopic biopsy, to evaluate the diagnostic accuracy of this procedure, and to assess the usefulness of immunohistochemical staining for carcinoembryonic antigen (CEA) in these neoplasms. The 11 benign neoplasms (31 per cent) were adenomas, five of which had focal hyperplastic features; the 24 malignant neoplasms (69 per cent) included ten intestinal-type carcinomas (resembling colonic carcinoma), seven anaplastic carcinomas (resembling diffuse gastric carcinoma), two adenocarcinomas in situ, and five lesions of unoriented, cytologically malignant epithelium. Malignancy was suspected endoscopically in 19 of 24 carcinomas, and the majority of the benign neoplasms were described as polyps or plaques. Resections (performed in 20 cases) demonstrated the accuracy of the biopsy diagnoses in 17 cases (85 per cent). In the three discordant cases, diagnosed by biopsy as adenoma in two cases and carcinoma in situ in one, coexistent in situ or infiltrating carcinomas were identified in the resected specimens. Carcinoembryonic antigen (20 cases) was identified mostly along glycocalyceal borders in normal and adenomatous tissues, whereas the carcinomas also showed strong cytoplasmic staining for CEA. Endoscopic biopsy is a valuable procedure in the diagnosis of duodenal and ampullary neoplasms. Correlation of the pathologic features of biopsy specimens with endoscopic appearances may result in more accurate diagnoses.