Microaggregate of immunostained macrophages in noninflamed gastroduodenal mucosa: a new useful histological marker for differentiating Crohn's colitis from ulcerative colitis

[Inflammatory bowel diseases and upper gastrointestinal tract]

Inflammatory bowel diseases (IBD), Crohn's disease and ulcerative colitis are inflammatory diseases with a flare-up evolution and an unknown etiology. Inflammatory lesions of the upper gastrointestinal tract are more and more often described in Crohn's disease and ulcerative colitis. The aim of this article was to review the inflammatory lesions of the esophagus, stomach and duodenum currently described in the IBD.

Macrophage control of Crohn's disease

The intestinal tract is the body's largest mucosal surface and permanently exposed to microbial and environmental signals. Maintaining a healthy intestine requires the presence of sentinel grounds keeper cells, capable of controlling immunity and tissue homeostasis through specialized functions. Intestinal macrophages are such cells and important players in steady-state functions and during acute and chronic inflammation. Crohn's disease, a chronic inflammatory condition of the intestinal tract is proposed to be the consequence of an altered immune system through microbial and environmental stimulation. This hypothesis suggests an involvement of macrophages in the regulation of this pathology. Within this chapter, we will discuss intestinal macrophage development and highlight data suggesting their implication in chronic intestinal pathologies like Crohn's disease.

Upper Gastrointestinal Tract Involvement in Inflammatory Bowel Diseases: Histologic Clues and Pitfalls

The upper gastrointestinal (UGI) manifestations of inflammatory bowel diseases (IBDs) are frequently obscured by classic ileal and colonic symptoms and are reported to involve only 0.5% to 4% of adult patients. However, because of the improvement of endoscopic techniques and the growing use of esophagogastroduodenososcopy with biopsy, both asymptomatic and clinically significant esophageal, gastric, and duodenal manifestations are increasingly recognized. The UGI involvement in IBD was historically synonymous with Crohn's disease (CD), but the doctrine of ulcerative colitis (UC) being limited to the colon has been challenged, and UC-related gastroduodenal lesions have been reported. The diagnosis of UGI IBD should ideally rely on a combination of the clinical history, endoscopic picture, and histologic features. Although endoscopic changes such as aphthoid or longitudinal ulcers and bamboo-joint-like pattern are suggestive of CD, histologic evaluation increases the sensitivity of the IBD diagnosis since histologic alterations may be present in endoscopically unremarkable mucosa. Conversely, in many cases, the histologic findings are nonspecific, and the knowledge of clinical history is vital for reaching an accurate diagnosis. The presence of epithelioid granuloma is highly suggestive of CD but is present in a minority of CD cases; thus, pathologists should be aware of how to diagnose UGI IBD in the absence of granulomata. This article reviews the most important clinical, endoscopic, and histologic features of IBD-associated esophagitis, gastritis, and duodenitis, as well as the IBD-related manifestations in the biliary tract and the postcolectomy setting.

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.

Focal enhanced gastritis and macrophage microaggregates in the gastric mucosa: potential role in the differential diagnosis between Crohn's disease and ulcerative colitis

CONTEXT AND OBJECTIVES

Focally enhanced gastritis and macrophage microaggregates are found in the upper gastrointestinal involvement of Crohn's disease, and may reflect an underlying defective innate immunity. These features, however, are also described in patients with Helicobacter pylori infection. The role of these gastric abnormalities in the diagnosis of Crohn's disease was assessed in a population with high prevalence of H. pylori infection.

METHODS

Thirty-seven Crohn's disease, 26 ulcerative colitis, and 30 control patients were included. The H. pylori status was evaluated by the rapid urease test and histology. The presence of focally enhanced gastritis and macrophage microaggregates was recorded.

RESULTS

Focally enhanced gastritis was present in 24% of Crohn's disease patients, 4% of ulcerative colitis patients and 11.5% of controls, presenting an overall sensitivity and specificity for Crohn's disease of 24% and 88%, respectively. Macrophage microaggregates were found in all groups, but were only detected in ulcerative colitis and controls in association with H. pylori infection, with an overall sensitivity and specificity for Crohn's disease of 61% and 69%, respectively. In the absence of H. pylori infection, focally enhanced gastritis and macrophage microaggregates were significantly associated with Crohn's disease (P<0.02 and P = 0.001 respectively).

CONCLUSIONS

Focally gastritis and macrophage microaggregates are suggestive of Crohn's disease only in H. pylori-negative specimens.

Nature of white opaque substance in gastric epithelial neoplasia as visualized by magnifying endoscopy with narrow-band imaging

BACKGROUND AND AIMS

Magnifying endoscopy (ME) with narrow-band imaging (NBI) revealed a white opaque substance (WOS) within the superficial part of the gastric neoplasia; however, its nature has remained obscure. A WOS noted within the duodenum was reported to comprise lipid droplets (LD) absorbed by the duodenal epithelium. We attempted to ascertain whether the WOS within gastric neoplasia could also comprise LD and whether the presence of this WOS could be correlated with a specific phenotype.

METHODS

Forty-three patients with early gastric epithelial neoplasia underwent ME with NBI. The presence or absence of WOS in the neoplasias was recorded based on the findings of ME with NBI. One biopsy specimen was taken from each of the neoplasias. Cryostat sections underwent oil red O staining for LD. Serial sections were immunostained using the first antibody of CD10, MUC2, CDX2, human gastric mucin, MUC5AC and MUC6. The tissue phenotype was classified as intestinal (I), gastric (G) and gastrointestinal (GI) type based on the results of immunostaining. In total, 49 gastric neoplasias from 43 patients were investigated.

RESULTS

Prevalence of LD in WOS-positive versus WOS-negative lesions was 96.2% (25/26) and 4.3% (1/23), respectively (P < 0.001, Fisher's exact test). WOS was present in GI- and I-type lesions, but not in G-type lesions.

CONCLUSIONS

WOS may be LD that have been accumulated in the superficial part of the gastric neoplasia of a certain intestinal phenotype.

Gluten-sensitive enteropathy (celiac disease): controversies in diagnosis and classification

CONTEXT

Celiac disease, or gluten-sensitive enteropathy, is a chronic inflammatory disorder of the small intestine characterized by malabsorption after ingestion of gluten in individuals with a certain genetic background. Clinical presentation can vary from full-blown malabsorption to subtle and atypical symptoms. Diagnosis currently relies on clinicopathologic studies including mucosal biopsy, serologic tests, and the effects of a diet free of gluten on the symptoms. Mucosal pathologic features are also variable, ranging from mild abnormalities, including intraepithelial lymphocytosis, to completely flat mucosa. Since patients with minimal histologic lesion of intraepithelial lymphocytosis often present with normal serologic findings, biopsy diagnosis becomes more important for identifying such individuals. Classification of mucosal pathology in gluten-sensitive enteropathy has been a subject of controversy among pathologists and needs to be revised according to the current understanding of the disease.

OBJECTIVES

To highlight the variations in clinical and pathologic presentation of gluten-sensitive enteropathy, to emphasize the importance of small-intestinal biopsy evaluation in the diagnosis, and to propose a new classification of mucosal pathology in gluten-sensitive enteropathy, in an effort to overcome the problems related to the classification systems currently available.

DATA SOURCES

A review of the literature on clinicopathologic features and the morphologic spectrum of gluten-sensitive enteropathy is presented.

CONCLUSIONS

Considering that there are many entities in the differential diagnosis of gluten-sensitive enteropathy, because of the varied clinicopathologic spectrum of the disease, diagnosis depends on good clinicopathologic communication. The classification that is presented in this review is a simple and practical approach to improve clinicopathologic correlation in gluten-sensitive enteropathy.

Metabolism of the colonic mucosa in patients with inflammatory bowel diseases: an in vitro proton magnetic resonance spectroscopy study

Metabolism of the colonic mucosa of patients with ulcerative colitis (UC; n=31) and Crohn's disease (CD; n=26) and normal mucosa (control, n=26) was investigated using in vitro high-resolution proton magnetic resonance spectroscopy. Of the 31 UC patients, 20 were in the active phase and 11 were in the remission phase of the disease. Out of 26 CD patients, 20 were in the active phase, while 6 were in the remission phase of the disease. Twenty-nine metabolites were assigned unambiguously in the perchloric acid extract of colonic mucosa. In the active phase of UC and CD, significantly lower (P<or=.05) concentration of amino acids (isoleucine, leucine, valine, alanine, glutamate and glutamine), membrane components (choline, glycerophosphorylcholine and myo-inositol), lactate and succinate were observed compared to normal mucosa of controls. Patients in the active phase of UC and CD also showed increased level of alpha-glucose compared to normal mucosa. Altered level of metabolites indicates decreased protein and carbohydrate metabolism, thereby decreased energy status and deterioration of mucosa integrity during chronic inflammation. In the remission phase of UC and CD, the concentration of most of the metabolites was similar to controls except for lower values of lactate, glycerophosphorylcholine and myo-inositol in UC and Lac in CD. Formate was significantly lower in patients with the active phase of UC compared to patients with the active phase of CD, suggesting the potential of in vitro MRS in the differentiation of these two diseases.

An approach to duodenal biopsies

The introduction of endoscopy of the upper digestive tract as a routine diagnostic procedure has increased the number of duodenal biopsy specimens. Consequently, the pathologist is often asked to evaluate them. In this review, a practical approach to the evaluation of a duodenal biopsy specimen is discussed. An overview of the handling of specimens is given and the normal histology and commonly encountered diseases are discussed. Finally, a description of commonly seen infections is provided, together with an algorithmic approach for diagnosis.

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.

Upper gastrointestinal tract endoscopy in inflammatory bowel disease

Upper gastrointestinal endoscopy is used to evaluate upper gastrointestinal symptoms in patients with inflammatory bowel disease. This article discusses the procedure, which may allow for the diagnosis of Crohn's disease of the esophagus, stomach, and/or duodenum. Biopsies of normal gastric mucosa in patients with indeterminate colitis may be helpful in making a diagnosis of Crohn's colitis. Upper gastrointestinal endoscopy may allow for therapeutic intervention in terms of bleeding and stricturing disease.

Emerging gastritides

The purpose of this review is to highlight two types of gastritis that have recently received much greater attention: lymphocytic gastritis and the gastritis associated with Crohn's disease. Lymphocytic gastritis is a distinctive pattern of inflammation that resembles that seen in celiac disease and lymphocytic colitis. It is associated with a diverse and unusual group of disorders in their own right, as well as having a possible relationship (real or phantom) with H. pylori infection. With respect to Crohn's disease, there is a growing recognition that, much more common than gastric granulomas, is the existence in one third or more of patients of a highly focal non-H. pylori gastritis. This recognition may help secure the diagnosis of Crohn's disease where it is equivocal, especially in children, in whom follow-up radiography and endoscopy cannot be done as readily as in adults.