Distinction between intestinal metaplasia in the cardia and in Barrett's esophagus: the role of histology and immunohistochemistry

An Update on the Role of Immunohistochemistry in the Evaluation of Pancreatic/Liver/Gastrointestinal Luminal Tract Disorders

CONTEXT.—

Immunohistochemistry serves as an ancillary diagnostic tool for a wide variety of neoplastic and nonneoplastic disorders, including infections, workup of inflammatory conditions, and subtyping neoplasms of the pancreas/liver/gastrointestinal luminal tract. In addition, immunohistochemistry is also used to detect a variety of prognostic and predictive molecular biomarkers for carcinomas of the pancreas, liver, and gastrointestinal luminal tract.

OBJECTIVE.—

To highlight an update on the role of immunohistochemistry in the evaluation of pancreatic/liver/gastrointestinal luminal tract disorders.

DATA SOURCES.—

Literature review and authors' research data and personal practice experience were used.

CONCLUSIONS.—

Immunohistochemistry is a valuable tool, assisting in the diagnosis of problematic tumors and benign lesions of the pancreas, liver, and gastrointestinal luminal tract, and also in the prediction of prognosis and therapeutic response for carcinomas of the pancreas, liver, and gastrointestinal luminal tract.

Clinical implications of molecular changes in pediatric Barrett's esophagus

Barrett's esophagus (BE) is a preneoplastic condition that predisposes to esophageal adenocarcinoma. Although data on the occurrence of BE in children are limited, recent studies have suggested an increase in the pediatric population. BE is thought to be a complex disease in which individual genetic predisposition interacts with environmental stimuli. Early premalignant clones produce biological and genetic heterogeneity, resulting in stepwise changes in differentiation, proliferation, and apoptosis, allowing disease progression under selective pressure. The value of endoscopic surveillance biopsy for dysplasia and carcinoma in patients with BE is controversial. Thus, the recognition of early and objective alternative risk markers, less susceptible of sampling error, will be of relevance in the management of BE patients. The possibility of performing molecular genetics on paraffin-embedded biopsies will expand our understanding of the natural history of BE and may lead to the use of biomarkers to inform treatment strategies.

A Clinical and Histopathologic Focus on Barrett Esophagus and Barrett-Related Dysplasia

Context.—Barrett esophagus is a metaplastic, premalignant lesion associated with approximately 0.5% annual incidence of progression to esophageal adenocarcinoma. Diagnosis and screening of Barrett esophagus and Barrett-related dysplasia relies on histologic evaluation of endoscopic mucosal biopsies, a process that is burdened with interobserver variability.

Objectives.—To review the histologic features and classification of Barrett esophagus and Barrett-related dysplasia, to discuss the underlying difficulties in diagnosis and pitfalls, and to provide a brief review of new developments related to therapeutic modalities for patients diagnosed with dysplasia.

Data Sources.—Sources include a review of relevant literature indexed in PubMed (US National Library of Medicine).

Conclusions.—In spite of interobserver variability, histologic assessment of dysplasia is currently the accepted method of surveillance, and subsequent patient management is dictated by this evaluation. Although not universal, endoscopic therapy is increasingly important in replacing esophagectomy for patients with high-grade dysplasia or early carcinoma.

The gene expression profile of cardia intestinal metaplasia is similar to that of Barrett's esophagus, not gastric intestinal metaplasia

The etiology and significance of cardia intestinal metaplasia (CIM) is disputed. CIM may represent a form of Barrett's esophagus due to reflux or could reflect generalized gastric intestinal metaplasia due to Helicobacter pylori. The aim of this study was to utilize gene expression data to compare CIM to Barrett's and gastric intestinal metaplasia. Endoscopic biopsies were classified by endoscopic and histologic criteria as CIM (n= 33), Barrett's (n= 25), or gastric intestinal metaplasia of the antrum or body (n= 18). The squamocolumnar and gastroesophageal junctions were aligned in CIM patients and patients with diffuse gastric intestinal metaplasia were excluded. H. pylori was tested for in the biopsies of all patients. After laser-capture microdissection, quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to measure the mRNA expression of a panel of nine genes that has been shown to differentiate Barrett's from other foregut mucosa. Cluster analysis with linear discriminant analysis of the expression data was used to classify each sample into groups based solely on similarity of gene expression. Cluster analysis was performed for three groups (CIM vs. Barrett's vs. gastric intestinal metaplasia) and two groups (CIM + Barrett's vs. gastric intestinal metaplasia). There was no difference in H. pylori infection among groups (P= 0.66). Clustering into three groups resulted in frequent misclassification between CIM and Barrett's while misclassification of gastric intestinal metaplasia was uncommon. The CIM and Barrett's groups were then combined for two group clustering and linear discriminant analysis correctly predicted 95% of CIM and Barrett's samples and 83% of gastric intestinal metaplasia samples based on gene expression alone. In conclusion, the gene expression profiles of CIM and Barrett's esophagus were similar in 95% of biopsies and differed significantly from that of gastric intestinal metaplasia. The indistinguishable gene expression profile of CIM and BE suggests that they may share a common etiology in the majority of patients with a similar biology, and calls into question the perception that CIM is an innocuous process.

What the gastroenterologist needs to know about the histology of Barrett's esophagus

PURPOSE OF REVIEW

The purpose of this review is to provide clinicians with an up-to-date summary of the terminology, classification, biological characteristics, and limitations of pathology regarding Barrett's esophagus and associated neoplastic precursor lesions in order to optimize decision making when evaluating patients with this disorder.

RECENT FINDINGS

This review summarizes some of the advancements and controversies regarding the definition and diagnostic criteria for Barrett's esophagus, difficulties that arise when trying to differentiate esophageal versus gastric epithelium in gastroesophageal junction (GEJ) biopsies, the histology and biology of nondysplastic Barrett's esophagus including columnar metaplasia without goblet cells, and the limitations and diagnostic variability in interpretation of conventional and nonconventional types of dysplasia in Barrett's esophagus.

SUMMARY

The definition of Barrett's esophagus is controversial, particularly with regard to the need to identify goblet cells in esophageal biopsies. In most cases, morphologic evaluation of GEJ biopsies cannot help distinguish whether the columnar epithelium comes from the distal esophagus versus the proximal stomach. Metaplastic esophageal columnar epithelium that does not contain goblet cells nevertheless is biologically intestinalized, shows molecular abnormalities, and has been shown to be at risk for progression to cancer, but the magnitude of that risk is unknown. Interobserver agreement on the presence, grade, and type of dysplasia remains moderate at best, particularly in light of the recent recognition of nonconventional types of dysplasia, such as foveolar, serrated, and early crypt dysplasia, which make interpretation difficult. Close cooperation between clinicians and pathologists is essential in order to ensure proper interpretation of biopsy results and to provide optimal surveillance and treatment decisions.

Intestinal differentiation in metaplastic, nongoblet columnar epithelium in the esophagus

Barrett esophagus (BE) is defined by the presence of metaplastic esophageal columnar epithelium with goblet cells within endoscopically recognizable areas of the esophagus. However, some carcinomas in BE, or from the gastroesophageal junction region, develop within mucosa devoid of goblet cells. However, the biologic properties, pathogenesis, and risk of malignancy of metaplastic, esophageal nongoblet columnar epithelium, is, essentially, unknown. In this study, 89 patients with metaplastic esophageal columnar epithelium were evaluated immunohistochemically for markers of intestinal differentiation, such as MUC2, DAS-1, Villin, and CDX2, a marker of gastric differentiation (MUC5AC), and Ki67, a marker of cell proliferation. Of the 89 patients, 59 had columnar metaplasia with goblet cells (BE), which were further separated into low-density goblet cell and high-density goblet cell groups based on the percentage of crypts with goblet cells, and 30 patients had columnar metaplasia of the esophagus without goblet cells. As controls, gastric biopsies from 19 age and sex matched patients without esophageal or gastric pathology were used. The rate of positivity of the markers and the location of Ki67 staining was evaluated only in non-goblet columnar epithelium from all patient groups. Patients with metaplastic esophageal columnar epithelium without goblet cells showed positivity for MUC5AC, MUC2, DAS-1, Villin, and CDX2 in 100%, 0%, 30%, 17%, and 43% of cases, respectively. 17% of cases showed aberrant surface Ki67 positivity. These values were significantly higher than gastric controls, which showed absence of staining for all markers except MUC5AC (100%). In patients with metaplastic esophageal columnar epithelium with goblet cells (BE) a significant increased rate of staining was observed for all markers, except MUC5AC. In addition, both MUC2 and surface Ki67 staining were significantly increased in BE patients with high-density goblet cells versus those with low-density goblet cells. In a separate analysis in which metaplastic esophageal nongoblet epithelium was evaluated in areas of mucosa devoid of goblet cells compared with areas of mucosa with goblet cells, from patients who had goblet cells elsewhere in the mucosa (N=59), no significant differences were observed with regard to the percentage of cases that stained with any of the markers in the nongoblet epithelium in areas devoid of goblet cells, similar to the patient group with metaplastic esophageal epithelium without goblet cells (N=30). Similar to above, in all cases, expression of intestinal markers increased in areas of mucosa adjacent to goblet cells. This study provides evidence that metaplastic esophageal columnar epithelium without goblet cells shows phenotypic evidence of intestinal differentiation and supports the theory that squamous epithelium converts initially to nongoblet columnar epithelium before goblet cell metaplasia. Further prospective studies are needed to evaluate the pathogenetic sequence, natural history, and risk of malignancy of metaplastic esophageal nongoblet epithelium.

Differences in genetic instability and cellular phenotype among Barrett's, cardiac, and gastric intestinal metaplasia in a Japanese population with Helicobacter pylori

AIMS

Intestinal metaplasia is considered to be a precursor lesion in both Barrett's and intestinal-type gastric cancer. The aim was to clarify the differences in molecular pathology between specialized intestinal metaplasia (SIM) in Barrett's oesophagus (BO), cardiac (CIM) and gastric intestinal metaplasia (GIM).

METHODS AND RESULTS

Eighty-eight SIM cases with BO, 30 CIM cases and 52 GIM cases in patients with or without Helicobacter pylori infectionwere analysed for genetic instability and Das-1. Microsatellite instability and a loss of heterozygosity were evaluated at five microsatellite loci. The incidence of genetic instability was 55.7% in SIM, 40.0% in CIM and 23.1% in GIM, revealing a significant difference between SIM and GIM (P < 0.0005). For each microsatellite marker analysed, there were obvious differences in frequency among the three conditions. Das-1 reactivity was significantly higher in SIM than in CIM or GIM (P < 0.0001, both). Interestingly, both genetic instability and Das-1 reactivity in SIM showed a significantly higher incidence in patients with H. pylori infection than in those without (P < 0.005 and P < 0.01, respectively).

CONCLUSIONS

SIM is distinct from CIM and GIM, and the pathogenesis of SIM, like that of GIM, is associated to some degree with H. pylori infection in a Japanese population.

Immunoreactivity of cytokeratins 7 and 20 in goblet cells and columnar blue cells in patients with endoscopic evidence of Barrett's esophagus

CONTEXT

Barrett's esophagus is characterized by the presence of goblet cells. However, when alcian-blue is utilized, another type of cells, called columnar blue cells, is frequently present in the distal esophagus of patients with endoscopic evidence of Barrett's esophagus. Cytokeratin 7 and 20 immunoreactivity has been previously studied in areas of intestinal metaplasia at the esophagogastric junction. However, the expression of these cytokeratins in columnar blue cells has not been characterized.

OBJECTIVE

To compare the expression of cytokeratin 7 and 20 in goblet cells and columnar blue cells in patients with endoscopic evidence of Barrett's esophagus.

METHODS

Biopsies from 86 patients with endoscopic evidence of Barrett's esophagus were evaluated. The biopsies were stained for cytokeratin 7 and 20.

RESULTS

Goblet cells were present in 75 cases and columnar blue cells in 50 cases. Overall, cytokeratin 7 expression was similar in goblet cells and columnar blue cells (P = 0.25), while cytokeratin 20 was more common in goblet cells (P <0.001). In individuals with both cell types, however, cytokeratin 7 staining was the same in goblet and columnar blue cells in 95% of the cases, and cytokeratin 20 staining was the same in 77%.

CONCLUSION

Goblet cells and columnar blue cells have similar immunohistochemical staining patterns for cytokeratins 7 and 20 in patients with endoscopic evidence of Barrett's esophagus.

Barrett esophagus: histology and pathology for the clinician

The incidence of adenocarcinoma of the esophagus and gastroesophageal junction has increased dramatically over the past 30 years. The major precursor to this type of adenocarcinoma is Barrett esophagus, which is defined as the conversion of normal squamous epithelium into metaplastic columnar epithelium. Abundant evidence suggests that adenocarcinoma in the setting of Barrett esophagus develops via a progressive sequence of histological and molecular events. Consequently, patients with Barrett esophagus routinely undergo endoscopic surveillance for early detection of neoplasia. Histological evaluation of mucosal biopsy samples from the esophagus and gastroesophageal junction for identification of goblet cells and evaluation of the presence, grade and extent of dysplasia is the mainstay of risk assessment for these patients. This Review provides physicians with a summary of the pertinent, clinically relevant histological features of Barrett esophagus and its neoplastic complications. The histology of Barrett esophagus and the gastroesophageal junction is summarized, and an overview of information necessary to interpret pathology reports from patients either with or without endoscopic evidence of Barrett esophagus is provided to appropriately guide management of patients. Close interaction between the clinician and the pathologist is essential for proper interpretation of biopsy results and to provide optimal surveillance or treatment strategies.

Pediatric columnar lined esophagus vs Barrett's esophagus: is it the time for a consensus definition

We describe the clinical, endoscopic, and histological features of all cases of Barrett's esophagus (BE) diagnosed at our institution between 2000 and 2007 following the criteria of the British Society of Gastroenterology. This society defines BE as a segment of columnar metaplasia (CLO) (whether intestinalized or not) of any length, visible endoscopically above the gastroesophageal junction and confirmed histologically. The diagnosis was challenged after immunostaining for Cdx2 (marker of intestinal differentiation). Information was collected with respect to age, symptoms, treatment, and endoscopic and histological features. Twelve children (10 males and 2 females) with a median age of 11.7 (2 to 17) years had been diagnosed with CLO-BE. Histology confirmed BE in 31 of 38 endoscopies. The initial diagnosis was reviewed according to Cdx2 results in 10 of 12 patients: Cdx2 strongly expressed in 4 cases with intestinal metaplasia (the diagnosis of BE was maintained); was negative in 4 other patients with "CLO" mucosa (reviewed diagnosis was that of expansion of the gastric cardia into the distal esophagus); and 2 patients had occasional Cdx2-positive cells showing cardia-type mucosa with goblet cells (early BE?). The estimated prevalence of CLO-BE in the pediatric population of South Yorkshire (United Kingdom) is 0.0024%, 0.8% in children referred for endoscopy and 5.5% in the children with reflux esophagitis. Characterization of the BE and confirmation of intestinal differentiation may have prognostic implications that can impact the surveillance program. Our results showed that intestinal differentiation as demonstrated with Cdx2 was only seen if goblet cells were present. A consensus definition and further studies to understand the molecular mechanisms involved in the development of BE at this age are needed.

Barrett's esophagus and cardiac intestinal metaplasia: two conditions within the same spectrum

BACKGROUND

Immunostaining for cytokeratin 7 (CK7) and cytokeratin 20 (CK20) has a characteristic pattern in Barrett's esophagus (BE), but reports regarding its sensitivity and specificity are inconsistent. Intestinal metaplasia of the gastric cardia (CIM) is histologically similar to BE, but with no abnormal endoscopic findings.

OBJECTIVES

To evaluate the sensitivity and specificity of a semi-quantitative CK7/CK20 immunostaining pattern for the diagnosis of BE, and to further elucidate the pathogenesis of CIM.

METHODS

Tissues were examined by hematoxylin and eosin and periodic acid schiff/alcian blue stains, and then were immunostained with CK7 and CK20 antibodies. Correlations with other clinical parameters were statistically analyzed.

RESULTS

When values were revised based on follow-up data and auxiliary testing, all BE cases (100%) displayed the characteristic BE CK7/CK20 immunostaining pattern, compared with 66% of CIM cases. In the subgroup of patients who were endoscopically and immunohistochemistry-positive but histologically negative, all patients except for one had documented BE when clinical history, auxiliary testing and follow-up were evaluated. There were no statistically significant differences between BE and CIM regarding Helicobacter pylori infection or the type of metaplasia (complete versus incomplete). The sensitivity of the CK7/CK20 pattern reached 100% in the subgroup of CIM patients with a history of acid reflux. Of 26 cases of CIM where follow-up was available, four cases (15%) progressed to BE, and one developed dysplasia. All four cases showed the BE pattern of CK7/CK20 staining and were negative for H pylori infection.

CONCLUSIONS

A semiquantitative CK7/CK20 pattern can be used to confirm BE even in the absence of histological evidence. The subgroup of CIM with acid reflux may develop into BE and may need closer follow-up.

Polymeric immunoglobulin receptor-negative tumors represent a more aggressive type of adenocarcinomas of distal esophagus and gastroesophageal junction

CONTEXT

Polymeric immunoglobulin receptor (PIgR) expression has been found in gastric mucosa and gastric cancers, but it is not known whether PIgR expression is related to background intestinal metaplasia nor the patterns of PIgR expression in tumors arising in the distal esophagus and gastroesophageal (GE) junction.

OBJECTIVES

To identify clinicopathologic features of tumors associated with PIgR expression and to determine whether PIgR expression is associated with intestinal differentiation of tumors and intestinal metaplasia in background mucosa in 3 groups of upper gastrointestinal adenocarcinomas. These groups are (1) gastric adenocarcinomas, (2) adenocarcinomas of the distal esophagus and GE junction with background intestinal metaplasia, and (3) adenocarcinomas of the distal esophagus and GE junction without background intestinal metaplasia.

DESIGN

Expression of PIgR and CDX2 in nonneoplastic mucosa, intestinal metaplasia, and adenocarcinomas was examined by immunohistochemistry in 42 cases: 14 gastric and 28 from the distal esophagus and GE junction, including 13 with esophageal or GE junction intestinal metaplasia.

RESULTS

PIgR and CDX2 were expressed in all cases of intestinal metaplasia. PIgR expression was positive in 40% of group 3 versus 77% of group 2 and 71% of gastric adenocarcinomas (P = .06), and the expression of CDX2 was similar in all tumor groups (80%-83%). Metastatic-positive lymph nodes were more frequent in PIgR-negative tumors (94% vs 58%, P = .01).

CONCLUSIONS

PIgR is uniformly expressed in intestinal metaplasia and in a subgroup of adenocarcinomas of the distal esophagus, GE junction, and stomach. Esophageal and GE junction adenocarcinomas that do not express PIgR show more frequent lymph node metastasis, suggesting that lack of expression of PIgR identifies a subgroup of more aggressive adenocarcinomas.

Morphologic features are useful in distinguishing Barrett esophagus from carditis with intestinal metaplasia

Barrett esophagus (BE) and carditis with intestinal metaplasia (CIM) differ in their risk of malignancy and implications for patient management, but are difficult to distinguish in mucosal biopsies from the gastroesophageal junction region. The present study was performed to evaluate the role of routine morphology in distinguishing BE from CIM in mucosal biopsies and to assess the degree of interobserver variability in recognizing morphologic parameters that are of significance in making this distinction. Several morphologic features, including presence of crypt disarray and atrophy, incomplete and diffuse intestinal metaplasia, multilayered epithelium, squamous epithelium overlying columnar crypts with intestinal metaplasia, hybrid glands, and esophageal glands/ducts, were significantly associated with a diagnosis of BE. The latter 3 features were observed exclusively in BE biopsies. Furthermore, multiple BE-associated morphologic features were often present together in BE but not CIM biopsies. There was substantial agreement (kappa=0.6) among expert gastrointestinal pathologists for distinguishing BE from CIM even in the absence of clinical/endoscopic information. The interobserver agreement in recognition of BE-associated morphologic features ranged from almost perfect for some features like esophageal glands/ducts (kappa=0.83) to slight for multilayered epithelium (kappa=0.17). In conclusion, our findings indicate that several morphologic features are helpful in distinguishing BE from CIM. The combined presence of multiple BE-associated morphologic features can be used in making this distinction with a high degree of accuracy. Larger prospective studies need to be performed to validate these findings and evaluate the reproducibility of this approach in routine clinical practice.

The use of cytokeratin stain to distinguish Barrett's esophagus from contiguous tissues: a systematic review

Our objective was to systematically review the existing literature regarding the use of cytokeratin (CK) stain in differentiating Barrett's esophagus (BE) from tissues of the gastric cardia, corpus, or antrum, with or without intestinal metaplasia (IM). Pubmed was searched for full publications in English (1983-2005) addressing the use of CK for differentiation of BE from contiguous tissues. Information was collected on the study sample, blinding, the methods used for CK staining, and for defining and applying the gold standard tests. Test characteristics were obtained or calculated. Sixteen studies (containing 46 comparisons) met the inclusion and exclusion criteria. Immunostaining for CK 7 and 20 was generally highly specific in distinguishing long-segment BE from antrum IM, fundus IM, or noncardiac gastric IM; 27 comparisons showed statistically significant differences. However, only 8 of 15 comparisons (6 of 12 studies) reported significant differences in CK staining patterns between BE and gastric cardia IM with a high sensitivity (89%-100%) and specificity (83%-100%) for long-segment BE and lower estimates for short-segment BE, while the other seven comparisons showed no significant differences and a very low sensitivity. Examination by a blinded pathologist was reported in five of six positive studies and in only one of six of the negative studies. In addition, variation in the patient populations, use of surgical resection versus endoscopic biopsies, and biopsy sampling technique in endoscopic studies may have accounted for these differences. Finally, two studies did not find significant differences in CK staining patterns between BE and normal cardiac mucosa. In conclusions, CK immunostaining has not performed well in differentiating BE, especially short-segment BE, from cardia IM. There seems to be a spectrum bias where the accuracy varies with different tested populations. CK immunostaining distinguished well between BE and IM in noncardiac segments of the stomach; however, these comparisons are not clinically relevant.

Immunopathological Patterns of the Stomach in Adenocarcinoma of the Esophagus, Cardia, and Gastric Antrum: Gastric Profiles in Siewert Type I and II Tumors

BACKGROUND

The morphologic and immunohistochemical profiles of gastric mucosa and of the tumor were assessed in Siewert type I, type II, and gastric antrum adenocarcinomas.

METHODS

Sixty-two patients, prospectively operated upon, were included in the study: 37 type II, 15 type I, and 10 antrum adenocarcinoma. Samples of the tumor, the surrounding area, and the gastric corpus and antrum were analyzed histologically, and immunostained for cytokeratins (CK)7/20 (staining positive for cells labeled > or = 50%).

RESULTS

Among the 37 type II adenocarcinomas were the following: (1) 13 of 37 (35%) had intestinal metaplasia (IM) in the stomach; (2) 24 of 37 (65%) did not show IM at any level; (3) 34 of 37 (92%) had Helicobacter pylori (HP) infection; (4) 13 of 37(35%) had CK7/20 expression of "Barrett's type" (CK7+/20-); 24 of 37 (65%) had a "no Barrett's type" profile (10 of 37 with CK7-/CK20+ and 14 of 37 with CK7+/CK20+); (5) 100% showed the same CK immunoprofile, both in IM and adenocarcinoma (measure of agreement k = 1, p = 0.000). Type I adenocarcinomas showed the following: (1) 87.5% CK Barrett's type, both in the tumor, and in the surrounding IM; (2) 100% gastric samples devoid of both IM and HP infection. Comparison between CK immunoprofiles in type I and type II tumors showed a difference within the two groups (p = 0.002). One hundred percent of antrum adenocarcinomas showed a no Barrett's type CK profile, both in the tumor and in the IM of the entire stomach.

CONCLUSIONS

Data suggest that type II adenocarcinoma cannot be always considered a gastroesophageal reflux disease-related tumor; other pathogenetic pathways should be taken into consideration.

Short segment Barrett's esophagus and distal gastric intestinal metaplasia

BACKGROUND

Short segment Barrett's esophagus is defined by the presence of <3 cm of columnar-appearing mucosa in the distal esophagus with intestinal metaplasia on histophatological examination. Barrett's esophagus is a risk factor to develop adenocarcinoma of the esophagus. While Barrett's esophagus develops as a result of chronic gastroesophageal reflux disease, intestinal metaplasia in the gastric cardia is a consequence of chronic Helicobacter pylori infection and is associated with distal gastric intestinal metaplasia. It can be difficult to determine whether short-segment columnar epithelium with intestinal metaplasia are lining the esophagus (a condition called short segment Barrett's esophagus) or the proximal stomach (a condition called intestinal metaplasia of the gastric cardia).

AIMS

To study the association of short segment Barrett's esophagus (length <3 cm) with gastric intestinal metaplasia (antrum or body) and infection by H. pylori.

PATIENTS AND METHODS

Eight-nine patients with short segment columnar-appearing mucosa in the esophagus, length <3 cm, were studied. Symptoms of gastroesophageal reflux disease were recorded. Biopsies were obtained immediately below the squamous-columnar lining, from gastric antrum and gastric corpus for investigation of intestinal metaplasia and H. pylori.

RESULTS

Forty-two from 89 (47.2%) patients were diagnosed with esophageal intestinal metaplasia by histopathology. The mean-age was significantly higher in the group with esophageal intestinal metaplasia. The two groups were similar in terms of gender (male: female), gastroesophageal reflux disease symptoms and H. pylori infection. Gastric intestinal metaplasia (antrum or body) was diagnosed in 21 from 42 (50.0%) patients in the group with esophageal intestinal metaplasia and 7 from 47 (14.9%) patients in the group with esophageal columnar appearing mucosa but without intestinal metaplasia.

CONCLUSION

Intestinal metaplasia is a frequent finding in patients with <3 cm of columnar-appearing mucosa in the distal esophagus. In the present study, short segment intestinal metaplasia in the esophagus is associated with distal gastric intestinal metaplasia. Gastroesophageal reflux disease symptoms and H. pylori infection did not differ among the two groups studied.

Distinction between short-segment Barrett’s esophageal and cardiac intestinal metaplasia

AIM: To investigate the roles of mucin histochemistry, cytokeratin 7/20 (CK7/20) immunoreactivity, clinical characteristics and endoscopy to distinguish short-segment Barrett’s esophageal (SSBE) from cardiac intestinal metaplasia (CIM).

METHODS: High iron diamine/Alcian blue (HID/AB) mucin-histochemical staining and immunohistochemical staining were used to classify intestinal metaplasia (IM) and to determine CK7/20 immunoreactivity pattern in SSBE and CIM, respectively, and these results were compared with endoscopical diagnosis and the positive rate of gastroesophageal reflux disease (GERD) symptoms and H pylori infection. Long-segment Barrett’s esophageal and IM of gastric antrum were designed as control.

RESULTS: The prevalence of type III IM was significantly higher in SSBE than in CIM (63.33% vs 23.08%, P<0.005). The CK7/20 immunoreactivity in SSBE showed mainly Barrett’s pattern (76.66%), and the GERD symptoms in most cases which showed Barrett’s pattern were positive, whereas H pylori infection was negative. However, the CK7/20 immunoreactivity in CIM was gastric pattern preponderantly (61.54%), but there were 23.08% cases that showed Barrett’s pattern. H pylori infection in all cases which showed gastric pattern was significantly higher than those which showed Barrett’s pattern (63.83% vs 19.30%, P<0.005), whereas the GERD symptoms in gastric pattern were significantly lower than that in Barrett’s pattern (21.28% vs 85.96%, P<0.005).

CONCLUSION: Distinction of SSBE from CIM should not be based on a single method; however, the combination of clinical characteristics, histology, mucin histochemistry, CK7/20 immunoreactivity, and endoscopic biopsy should be applied. Type III IM, presence of GERD symptoms, and Barrett’s CK7/20 immunoreactivity pattern may support the diagnosis of SSBE, whereas non-type III IM, positive H pylori infection, and gastric CK7/20 immunoreactivity pattern may imply CIM.

Cytokeratin phenotyping does not help in distinguishing oesophageal adenocarcinoma from cancer of the gastric cardia

BACKGROUND

It is sometimes difficult to distinguish between cardia cancer and oesophageal cancer.

AIMS

To evaluate whether cytokeratin (CK) expression of the tumour can be of value in differentiating between the two tumour types.

METHODS

Consecutive patients with a malignant tumour in the oesophagus or stomach were recruited. Biopsy specimens were taken for routine haematoxylin and eosin staining. One tissue block with representative tissue was selected for immunohistochemical staining (CK7 and CK20).

RESULTS

Endoscopically located adenocarcinoma of the oesophagus was present in 84 patients (64 men, 20 women; mean age, 68 years; range, 44-91). Cancer located primarily in the gastric cardia was present in 63 patients (42 men, 21 women; mean age, 68 years; range, 42-88). The histological diagnosis was metastasis from a primary tumour outside the oesophagus or stomach in 19 patients. The patients were divided into three groups for the immunohistochemical analysis. Patients in group A had definite oesophageal cancer, group B patients had a definite carcinoma located in the gastric cardia, and group C patients had an obstructing tumour distal in the oesophagus at the level of the diaphragm, which could not be passed with the endoscope. Paraffin wax embedded material was available from 122 patients for immunostaining and CK analysis. There was no significant difference in expression or distribution of CK7 or CK20 in the three groups of patients.

CONCLUSION

CK phenotyping cannot distinguish between cancer arising from a Barrett's oesophagus and carcinoma originating in the gastric cardia.

Claudin expression in Barrett's esophagus and adenocarcinoma

Claudins (CLDNs) are key molecules in cell adhesion, polarity, and control of paracellular solute transport. Several studies suggested that changes in claudin pattern have a role in cancer development. This study aimed to detect alterations in CLDN 1, 2, 3, 4, and 7 expression patterns in Barrett's esophagus (BE) and adenocarcinoma (ACC) compared with that in foveolar epithelium (FOV), normal squamous epithelium (SQ), and squamous cell carcinoma (SQCC). One hundred twenty five surgically or endoscopically removed, paraffin-embedded cases were studied by immunohistochemistry and analyzed statistically. BE, ACC, and FOV were dissected from 30 paraffin-embedded samples for further mRNA expression analysis. CLDN 7 was the dominating type in all epithelia and carcinomas, but its expression did not differ in normal and altered tissues. CLDN 1 expression was significantly increased in SQCC compared with that in SQ. CLDNs 3 and 4 were significantly elevated both in BE and ACC compared with that in FOV. CLDN 2 expression increased significantly in ACCs compared with that in BE. This is the first report proving similarities and differences regarding claudin expression pattern in BE and ACC compared with that in FOV and SQ. Our data prove a close link in CLDN pattern between BE and ACC, adding further evidence that BE is an alteration preceding esophageal ACC.

Unraveling the mystery of the gastroesophageal junction: a pathologist's perspective

The gastroesophageal junction (GEJ), which is defined as the point where the distal esophagus joins the proximal stomach (cardia), is a short anatomic area that is commonly exposed to the injurious effects of GERD and/or Helicobacter pylori infection. These disorders often lead to inflammation and intestinal metaplasia (IM) of this anatomic region. The true gastric cardia is an extremely short segment (<0.4 mm) of mucosa that is typically composed of pure mucous glands, or mixed mucous/oxyntic glands that are histologically indistinguishable from metaplastic mucinous columnar epithelium of the distal esophagus. In patients with GERD, whether physiologic or pathologic, the length of cardia-type epithelium increases and extends proximally above the level of the anatomic GEJ into the distal esophagus. Columnar metaplasia of the distal esophagus represents a squamous to columnar metaplastic reaction that develops from an esophageal stem cell and may pass through an intermediate phase characterized by the presence of a type of epithelium that possesses a mixture of squamous and columnar features, termed multilayered epithelium. In contrast, IM of the gastric cardia represents a columnar to columnar cell metaplastic reaction that develops from a gastric stem cell located in the deep foveolar compartment of the gastric mucosa. Intestinal metaplasia, particularly the incomplete type, is widely believed to represent the precursor lesion upon which dysplasia and cancer arises. The frequency of IM is probably greater in metaplastic columnar epithelium in the esophagus secondary to GERD, than in cases of true gastric carditis secondary to H. pylori, and may be a reason why there is a higher risk of carcinoma in the former compared to the latter. A variety of clinical, endoscopic, histologic, and histochemical methods can be used to distinguish GERD-induced columnar metaplasia of the distal esophagus from H. pylori-induced inflammation of true gastric cardia, and these are outlined in this review, but further controlled studies are needed to critically evaluate these techniques. Further prospective trials are needed to adequately evaluate the different etiologic and pathogenetic mechanisms and, most importantly, the risk of malignancy in these two conditions.

Cytokeratin immunoreactivity patterns in short-segment Barrett's esophagus in Japanese patients

BACKGROUND

The origin of intestinal metaplasia at the esophagogastric junction has clinical importance. However, it can be difficult to differentiate between intestinal metaplasia of short-segment Barrett's esophagus and cardiac intestinal metaplasia due to Helicobacter pylori infection. Specific patterns of cytokeratin (CK)7 and CK20 have been detected in long-segment Barrett's esophagus. The aim of the present study was to assess the immunostaining patterns associated with short-segment Barrett's esophagus.

AIMS

Paraffin-embedded biopsy specimens were prepared from 128 patients with intestinal metaplasia of long-segment Barrett's esophagus (n = 3), short-segment Barrett's esophagus without H. pylori infection (n = 22), short-segment Barrett's esophagus with H. pylori infection (n = 22), and cardiac mucosa (n = 49) and gastric mucosa from antrum and fundus (n = 44) with H. pylori infection. Sections were prepared and immunostained for CK7 and CK20.

RESULT

A Barrett's CK7/20 pattern was present in all three patients (100%) with long-segment Barrett's esophagus, 21 of 22 patients (95%) with short-segment Barrett's esophagus without H. pylori infection, and six of 22 patients (27%) with short-segment Barrett's esophagus with H. pylori infection (P < 0.05).

CONCLUSION

Intestinal metaplasia of short-segment Barrett's esophagus in patients without H. pylori infection is thought to be similar to that seen in long-segment Barrett's esophagus.

Epidemiology, pathophysiology, and treatment of Barrett's esophagus: reducing mortality from esophageal adenocarcinoma

The definition of BE has evolved over time. BE is the key premalignant lesion for developing EAC. The epidemiology and pathophysiology of BE is outlined, and risk factors for BE and EAC are reviewed. GERD plays a crucial role in the pathophysiology and the clinical identification of BE. Endoscopy with biopsy is the best tool for diagnosing and surveying patients with BE. Detection of early neoplasia is the present approach to reduce EAC mortality. Novel technology should assist in the early detection of dysplasia to enable targeted therapy. Effective chemopreventive strategies may reduce the risk of progression to EAC.

Interinstitutional variability and effect of tissue fixative on the interpretation of a Barrett cytokeratin 7/20 immunoreactivity pattern in Barrett esophagus

A unique pattern of cytokeratin (CK) 7/20 immunostaining (diffuse staining with CK7 and surface and superficial crypt staining with CK20) has been reported to be useful in differentiating Barrett esophagus (BE) from intestinal metaplasia of the stomach. However, there are conflicting results regarding the prevalence of a BE CK7/20 staining pattern in BE between different studies. Therefore, this study was performed to determine the degree of variability in interpretation of a BE CK7/20 pattern and to determine the reasons for variability when present. Esophageal and gastric mucosal biopsies from 67 patients with BE and antral intestinal metaplasia at 2 institutions were immunostained for CK7/20. All cases were evaluated for the presence of a BE CK7/20 pattern by 2 gastrointestinal pathologists from each institution, and the degree of agreement between institutions was determined. To determine the effect of tissue fixation and staining methods on the pattern of CK7/20 staining, unstained slides were exchanged between institutions, stained separately by each institution, and reexamined by all pathologists. There was excellent agreement on the presence of a BE CK7/20 staining pattern between pathologists at the same institution but only moderate agreement between pathologists at different institutions (71% overall, kappa = 0.58). Among BE cases, a BE CK7/20 staining pattern was identified in 50 (96%) of 52 cases by Cleveland Clinic Foundation pathologists but only 35 (67%) of 52 cases by Brigham and Women's Hospital pathologists. The major source of disagreement related to the interpretation of weak or variable CK7 staining of deep intestinalized mucosa in BE biopsies that were fixed in Hollande, but not those that were fixed in formalin. After the creation of a new set of criteria for a positive BE CK7/20 staining pattern, which took into account the effects of Hollande's fixative, the degree of agreement between pathologists at each of the 2 institutions was excellent (100%, kappa value = 1.0). Therefore, the CK7/20 staining pattern is influenced by the type of fixative used. Only a moderate level of interobserver agreement among pathologists regarding a BE CK7/20 pattern can be achieved if one is not aware of these effects. Nevertheless, specific criteria for interpretation of CK7/20 staining can be successfully applied between institutions and need to be developed before use of this technique in clinical practice.