Mucin histochemistry of the columnar epithelium of the oesophagus (Barrett's oesophagus): a prospective biopsy study

The path(ology) from reflux oesophagitis to Barrett oesophagus to oesophageal adenocarcinoma

This review seeks to summarise the steps in the path from reflux oesophagitis to Barrett oesophagus to oesophageal adenocarcinoma. The epidemiology, clinical presentation, definitions, pathological features, diagnostic pitfalls, and emerging concepts are reviewed for each entity. The histological features of reflux oesophagitis can be variable and are not specific. Cases of reflux oesophagitis with numerous eosinophils are difficult to distinguish from eosinophilic oesophagitis and other oesophagitides with eosinophils (Crohn's disease, medication effect, and connective tissue disorders). In reflux oesophagitis, the findings are often most pronounced in the distal oesophagus, the eosinophils are randomly distributed throughout the epithelium, and eosinophilic abscesses and degranulated eosinophils are rare. For reflux oesophagitis with prominent lymphocytes, clinical history and ancillary clinical studies are paramount to distinguish reflux oesophagitis from other causes of lymphocytic oesophagitis pattern. For Barrett oesophagus, the definition remains a hotly debated topic for which the requirement for intestinal metaplasia to make the diagnosis is not applied unanimously across the globe. Assessing for dysplasia is a challenging aspect of the histological interpretation that guides clinical management. We describe the histological features that we find useful in making this evaluation. Oesophageal adenocarcinoma has been steadily increasing in incidence and has a poor prognosis. The extent of invasion can be overdiagnosed due to a duplicated muscularis mucosae. We also describe the technical factors that can lead to challenges in distinguishing the mucosal and deep margins of endoscopic resections. Lastly, we give an overview of targeted therapies with emerging importance and the ancillary tests that can identify the cases best suited for each therapy.

Epidemiology of Barrett's Esophagus and Esophageal Adenocarcinoma: Implications for Screening and Surveillance

In the United States, the incidence of esophageal adenocarcinoma increased markedly since the 1970s with a recent stabilization. Despite evolving screening and surveillance strategies to diagnose, risk triage, and intervene in Barrett's esophagus patients to prevent esophageal adenocarcinoma, most cases present with advanced disease and poor resultant survival. Epidemiologic studies have identified the main risk factors for these conditions, including increasing age, male sex, white race, gastroesophageal reflux disease, abdominal obesity, cigarette smoking, and lack of infection with Helicobacter pylori. This review summarizes the current epidemiologic evidence with implications for screening and surveillance in Barrett's esophagus and esophageal adenocarcinoma.

Histochemistry in the diagnosis of non-neoplastic gastrointestinal disorders

The alimentary tract serves as host to a large number of diseases. In the non-neoplastic group of disorders, conventional histochemistry continues to play an important diagnostic role. It is particularly important in recognizing specific infectious diseases, such as Helicobacter gastritis, Whipple disease, intestinal tuberculosis and other forms of mycobacteriosis, malakoplakia, intestinal spirochetosis, fungal enteritides, amebiasis, cryptosporidiosis, isosporiasis, and microsporidiosis. Those conditions and their histochemical properties are discussed in this review, along with the use of histochemistry in the characterization of structural gastrointestinal disorders. The latter include mucosal metaplasias, amyloidosis, glycogenic acanthosis of the esophagus, lymphocytic-collagenous colitis, gastric neuroendocrine hyperplasia, and pill gastritis.

Prevalence and Risk Factors for Barrett's Esophagus in Patients with GERD in Northern India; Do Methylene Blue-directed Biopsies Improve Detection of Barrett's Esophagus Compared the Conventional Method?

BACKGROUND The reported rates of Barrett's esophagus (BE) ranged from 2.6% to 23% in Indian patients with gastro-esophageal reflux disease (GERD) symptoms. The role of methylene blue chromoendoscopy during endoscopy, either for the diagnosis of Barrett's esophagus or for the detection of dysplasia and early cancer, remains controversial.

AIM

Our study was designed to find out the endoscopic as well as histological prevalence of BE in India in a specified patient population affected by GERD, and whether methylene blue chromoendoscopy improves detection of specialized intestinal metaplasia in endoscopically suspected Barrett's esophagus in GERD patients. METHODS Three hundred and seventy eight patients with characteristic symptoms of GERD from Northern India were subjected to upper endoscopy. On endoscopic suspicion of columnar lined epithelium (CLE) either 4-quadrant conventional biopsies at 2 cm interval or Methylene Blue (MB) directed biopsies were obtained randomly. The two groups were compared for the detection of Specialized Intestinal Metaplasia (SIM), which was diagnosed if the intestinal goblet cells were present. RESULTS Out of 378 patients with GERD, 56 (14.81%) were suspected of CLE on endoscopy. After taking biopsy samples from the 56 patients, only 9 (2.38%) had specialized intestinal metaplasia on histopathological examination. Five (15.15%) patients in the conventional group and four (17.39%) patients in the chromoendoscopy group (p=0.55) were diagnosed as having BE. On univariate analysis the predictors of SIM were symptoms of reflux and length of CLE. CONCLUSION The prevalence of biopsy proven BE and CLE in Northern India was 2.38% and 14.81%, respectively in patients with symptoms of GERD. The results of MB directed biopsies were similar to conventional biopsies in detecting SIM.

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.

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.

Reflux esophagitis or Helicobacter infection? - diagnostic value of the inflammatory pattern in metaplastic mucosa at the squamocolumnar junction

OBJECTIVES

Metaplastic glandular mucosa with goblet cells at the squamocolumnar junction is induced either by reflux or by Helicobacter infection. We investigated whether the accompanying inflammation may give information about the etiology of these metaplastic changes and whether there are further criteria which are helpful in differentiating Helicobacter-induced vs. reflux-caused metaplasia.

METHODS

One hundred and nine patients with intestinal metaplasia diagnosed in biopsies obtained immediately below the Z-line were evaluated. Further biopsies were taken from the gastric body and antrum. Patients were diagnosed as having a normal Z-line, or as showing short tongues or segments of Barrett's esophagus endoscopically. Inflammation was graded according to the updated Sydney-system. Metaplasia was typed using Gomori's-aldehyde-fuchsin-Alcianblue staining.

RESULTS

Compared to patients with Barrett's esophagus, the active (p=0.0002) and chronic inflammation (p=0.0004) at the squamocolumnar junction was higher in patients with a normal Z-line and frequently accompanied by lymphoid aggregates (p<0.0001) and regular cardia- (p=0.0044) and/or corpus-type glands (p=0.0004). Pseudogoblet cells were more frequent in Barrett's esophagus (p=0.0159).

CONCLUSIONS

The endoscopic aspect of the Z-line, the inflammatory pattern, and the type of glands in biopsies from the squamocolumnar junction, as well as the presence of pseudogoblet cells are helpful tools in distinguishing Barrett's mucosa from Helicobacter-associated intestinal metaplasia.

Barrett's oesophagus?a pathologist's view

Barrett's oesophagus, a precancerous condition for oesophageal adenocarcinoma, detected on endoscopy and confirmed on histology, shows intestinal metaplasia of the lower oesophagus. The significance of microscopic foci of intestinal metaplasia at the gastro-oesophageal junction, corresponding either to so-called 'ultrashort' segment Barrett's oesophagus, or to carditis with intestinal metaplasia, is still a matter of debate. The surveillance of patients with Barrett's oesophagus is still based on systematic biopsy sampling of Barrett's mucosa on endoscopy, looking for dysplasia. Although well-established classifications of dysplasia are now used by most pathologists, there remain numerous problems with this subjective marker (sampling, diagnostic reproducibility, natural history, etc). Therefore, many alternative biomarkers have been proposed, but only DNA aneuploidy, proliferation markers and p53 loss of heterozygosity/overexpression have been shown to be of some use at the present time. Some endoscopic improvements already allow a better selection of biopsies, and it may be that in future new technologies will allow 'virtual biopsies'. On the other hand, the role of pathologists now extends to the evaluation of new therapeutic modalities of early neoplastic lesions in Barrett's oesophagus, especially endoscopic mucosal resection.

Pathology of the gastroesophageal junction

The gastroesophageal junction (GEJ) is a poorly defined anatomic area that represents the junction etween the distal esophagus and the proximal stomach (cardia). The true anatomic GEJ corresponds to the most proximal aspect of the gastric folds, which represents an endoscopically apparent transition oint in most individuals. Many, if not most, adults, particularly those with either physiologic or logic GERD, have a proximally displaced Z-line indicating that the histologic squamocolumnar nction (SCJ) is located above the anatomic GEJ. The histologic characteristics of short segments of columnar mucosa located above the anatomic GEJ in these individuals are similar to the gastric cardia, ng composed of either pure mucous glands or mixed mucous glands/oxyntic glands. Although controversial, some authors believe that the cardia is normally composed, at birth, of surface mucinous columnar epithelium and underlying oxyntic glands identical to the gastric corpus, whereas others maintain that the true anatomic cardia is normally composed of mucinous columnar epithelium with underlying mucous glands or mixed mucous and oxyntic glands. However, the preponderance of evidence supports the latter theory and that the length of mucosa composed of either mucous, or mixed mucous glands/oxyntic glands, increases with age and is presumed to be related to ongoing GERD. Inflammation of the true gastric cardia (carditis), which is most often due to H. pylori infection, is difficult to distinguish from columnar metaplasia of the distal esophagus secondary to GERD. From a pathologist's perspective, the differential diagnosis of true gastric carditis from esophageal columnar metaplasia of the distal esophagus in GEJ biopsies is difficult, but a variety of clinical, pathologic, and immunohistochemical methods can be used to help separate these two disorders. Nearly one-third of patients who present for upper GI endoscopy without endoscopic evidence of BE reveal foci of intestinal metaplasia in the GEJ. There are some studies to suggest that the risk of dysplasia and cancer is different in patients with intestinal metaplasia in the cardia related to H. pylori infection versus those with metaplastic columnar epithelium in the distal esophagus related to GERD. Chronic inflammation is generally considered the predominant underlying stimulus for the development of columnar metaplasia in the GEJ, regardless of the etiology. Columnar metaplasia and intestinal metaplasia in the distal esophagus represents a squamous to columnar cell transition and there is some evidence that this occurs through an intermediate, or transitional, phase of intestinalization termed multilayered epithelium. In contrast, intestinal metaplasia that develops in the true gastric cardia secondary to H. pylori infection represents a columnar to columnar metaplastic reaction. This review will focus on the clinical, pathologic, and pathogenetic aspects of GERD and H. pylori-induced inflammation of the GEJ region.

Barrett's oesophagus: from metaplasia to dysplasia and cancer

Barrett's oesophagus is a premalignant condition that predisposes to the development of oesophageal adenocarcinoma. It is detected on endoscopy and confirmed histologically by the presence in the lower oesophagus of a metaplastic mucosa, the so-called specialised epithelium, which resembles incomplete intestinal metaplasia in the stomach. These similarities with incomplete intestinal metaplasia are present on histology, mucin histochemistry, and immunohistochemistry with various differentiation markers (cytokeratins and MUC antigens). On morphology, the carcinogenetic process of Barrett's mucosa progresses through increasing grades of epithelial dysplasia. Dysplasia, a synonym of intraepithelial neoplasia, is the only marker that can be used at the present time to delineate a population of patients at high risk of cancer. Among the numerous molecular events that have been shown to play a role in the neoplastic transformation of Barrett's mucosa, only changes in DNA ploidy, increased proliferation, and alterations of the p53 gene have been suggested to be of potential help in the surveillance of patients.

Celiac disease and intestinal metaplasia of the esophagus (Barrett's esophagus)

Previous studies on celiac patients demonstrated that exposure to gliadin alters the motility of the upper gastrointestinal tract, leading to increased acid reflux. No literature is available regarding the possible presence of specialized intestinal metaplasia of the esophagus as a consequence of chronic reflux in adult celiac patients. Our purpose was to evaluate endoscopically and histologically the esophagi of a group of untreated celiac patients. We studied 60 celiac patients, 13 men and 47 women (mean age, 40 +/- 14 [SD] years; range, 18-80 years), at their first endoscopy (following a normal diet). The distal esophagus was evaluated and multiple biopsies were taken. Hematoxylin-eosin and alcian blue stainings were performed. A group of nonceliac, age- and sex-matched patients was used as a control. We found intestinal metaplasia in the distal esophagus of 16 of 60 (26.6%) celiacs (mean age, 45 +/- 13 years; range, 27-75 years), in comparison with a control-group prevalence of 10.9% (OR, 3.9; 95% CI, 1.4-11.2%). Among the celiac group with metaplasia, only one patient had reflux-like symptoms. None had esophagitis. In conclusion, we observed an increased prevalence of esophageal metaplasia in patients with celiac disease. This finding could be the result of motor abnormalities leading to chronic acid reflux, combined with a mucosa which is sensitive to gliadin.

Expression of the intestinal marker Cdx2 in the columnar-lined esophagus with and without intestinal (Barrett's) metaplasia

Barrett's esophagus is diagnosed when goblet cells are found in the lower esophageal mucosa. However, the distribution of these cells is patchy and they may not represent the earliest marker of intestinal metaplasia. Cdx2 is a transcription factor whose expression in normal tissues is restricted to intestinal-type epithelium. Its distribution in the columnar-lined esophagus with and without intestinal metaplasia has been seldom studied. We evaluated Cdx2 expression in lower esophageal biopsies from 90 patients with endoscopic diagnosis of short segment Barrett's esophagus, including 45 consecutive cases showing intestinal metaplasia (goblet cells present in hematoxylin eosin and/or Alcian blue stains) and 45 consecutive cases without goblet cells. 25 samples of cardiac-type mucosa without intestinal metaplasia biopsied from the stomach served as controls. All cases with intestinal metaplasia revealed Cdx2 reactivity in goblet cells and adjacent nongoblet columnar cells. Dysplastic foci, seen in five cases from this group, were Cdx2 positive. In the group without goblet cells, Cdx2 was focally expressed by columnar cells in 17 (38%) cases. All control cases were Cdx2 negative. Strips of Alcian blue-positive nongoblet columnar cells ('columnar blues') were observed in 11 (24%) of the cases without intestinal metaplasia. All these foci were Cdx2 negative. In conclusion, Cdx2 is a highly sensitive marker for Barrett's esophagus. It is also expressed in a significant minority of cases of columnar-lined esophagus without goblet cells, suggesting that it may detect intestinal phenotypic modifications in the absence of goblet cells. Accordingly, Cdx2 immunostaining could help identify patients with Barrett's metaplasia in cases where no goblet cells are visible in biopsies from the columnar-lined esophagus. Finally, lack of Cdx2 expression in the 'columnar blues' suggests that these cells are not diagnostic of intestinal metaplasia.

A critical review of the diagnosis and management of Barrett's esophagus: the AGA Chicago Workshop

BACKGROUND & AIMS

The diagnosis and management of Barrett's esophagus (BE) are controversial. We conducted a critical review of the literature in BE to provide guidance on clinically relevant issues.

METHODS

A multidisciplinary group of 18 participants evaluated the strength and the grade of evidence for 42 statements pertaining to the diagnosis, screening, surveillance, and treatment of BE. Each member anonymously voted to accept or reject statements based on the strength of evidence and his own expert opinion.

RESULTS

There was strong consensus on most statements for acceptance or rejection. Members rejected statements that screening for BE has been shown to improve mortality from adenocarcinoma or to be cost-effective. Contrary to published clinical guidelines, they did not feel that screening should be recommended for adults over age 50, regardless of age or duration of heartburn. Members were divided on whether surveillance prolongs survival, although the majority agreed that it detects curable neoplasia and can be cost-effective in selected patients. The majority did not feel that acid-reduction therapy reduces the risk of esophageal adenocarcinoma but did agree that nonsteroidal antiinflammatory drugs are associated with a cancer risk reduction and are of promising (but unproven) value. Participants rejected the notion that mucosal ablation with acid suppression prevents adenocarcinoma in BE but agreed that this may be an appropriate strategy in a subgroup of patients with high-grade dysplasia.

CONCLUSIONS

Based on this review of BE, the opinions of workshop members on issues pertaining to screening and surveillance are at variance with published clinical guidelines.

Barrett's esophagus: histopathologic definitions and diagnostic criteria

Adenocarcinoma of the distal esophagus is rising more rapidly in incidence than any other visceral malignancy in the Western world. It is well established that most, if not all, of these tumors develop in Barrett's esophagus via the metaplasia-dysplasia-carcinoma sequence and could theoretically be detected at an early stage, but despite this, the majority of these tumors are still detected late in their course. This highlights the fact that the goal of effective surveillance for patients at risk for developing an adenocarcinoma of the distal esophagus is still far off. In addition, adenocarcinomas of the esophagogastric junction and gastric cardia are also rising in incidence, but their carcinogenesis and their relation to Barrett's esophagus are still being defined, as are the meaning and significance of the relatively new entities "short-segment Barrett's" and "ultra-short-segment Barrett's". This review attempts to clarify the main histopathologic issues concerned with the definition of Barrett's esophagus, its distinction from intestinal metaplasia of the gastric cardia, as well as the criteria for the histologic diagnosis of dysplasia and carcinoma in Barrett's esophagus.

The presence and mucin histochemistry of cardiac type mucosa at the esophagogastric junction

OBJECTIVES

Traditionally, the gastric cardia has been described as a native part of the stomach connecting to the esophagus. In recent literature, however, it is suggested that the cardia is an acquired lesion that develops due to gastroesophageal reflux disease. As a contribution to this debate, we evaluated the presence of cardiac mucosa at the esophagogastric junction (EGJ) in a random group of patients who presented at our endoscopy unit.

METHODS

In 253 unselected patients, biopsies were taken from the EGJ. In order to prevent sampling error, we selected only those EGJ biopsies in which the squamocolumnar junction (SCJ) was present in the histological biopsy material. Fifty-five patients were excluded since the SCJ was located proximal to the EGJ in the esophagus. The type of columnar mucosa immediately distal to the SCJ, and its mucin histochemistry, were assessed. The columnar mucosa was categorized as purely cardiac, oxyntocardiac, or fundic mucosa.

RESULTS

In 63 of the 198 patients, the SCJ was actually present in the EGJ biopsies. Purely cardiac mucosa was present in 39 (62%) biopsies and oxyntocardiac mucosa was present in 24 (38%) biopsies. Fundic mucosa was not seen directly adjacent to squamous epithelium. Acid mucins were present in 23 (37%) patients and they correlated with histological esophagitis and presence of H. pylori in the cardia.

CONCLUSIONS

Cardiac mucosa was uniformly present adjacent to the squamous epithelium at the EGJ. This argues against the hypothesis that the gastric cardia is an acquired metaplastic lesion. The presence of acid mucins was frequently observed and could be a pathological condition as it was associated with histological esophagitis and the presence of H. pylori in the cardia.

Cdx2 as a marker of epithelial intestinal differentiation in the esophagus

The histologic diagnosis of Barrett's esophagus requires the presence of goblet cells, but this finding may not be the earliest indicator of intestinal metaplasia. We used immunohistochemistry to detect Cdx2, a transcriptional regulator important in the early differentiation and maintenance of intestinal epithelium, in 134 esophageal biopsy or resection specimens, including 62 with junctional-type epithelium (13 of which had equivocal histologic features of Barrett's epithelium), 34 with Barrett's epithelium without dysplasia, and 38 with Barrett's epithelium and dysplasia or carcinoma (13 low-grade dysplasias, 19 high-grade dysplasias, and 6 adenocarcinomas). We also performed PAS-alcian blue staining (pH 2.5) on adjacent sections. Cdx2 was observed in all cases of Barrett's epithelium. In some dysplasias (chiefly high-grade) and adenocarcinomas, there was diminution or focal loss of detectable protein. Cdx2 was detected in 20 of 62 cases (30%) of junctional-type epithelium, including 10 of 13 (77%) with equivocal histologic features of Barrett's epithelium. Acid mucin was present in goblet cells and non-goblet columnar cells in all cases of Barrett's esophagus and in non-goblet columnar cells in 48 of 62 cases (77%) with junctional-type epithelium only, including 17 of 20 (85%) that were Cdx2 positive and 31 of 42 (74%) that were Cdx2 negative. These results provide evidence that Cdx2 protein is a sensitive marker of intestinal metaplasia in the upper gastrointestinal tract and may be useful in detecting histologically equivocal cases of Barrett's esophagus. Cdx2 is present in dysplasia and adenocarcinoma, with some loss of protein primarily in high-grade dysplasia and adenocarcinoma. Acid mucin in non-goblet columnar cells is a common feature of Barrett's and junctional-type epithelium and may not always be indicative of intestinal metaplasia.

Detection of sulfated glycoproteins in intestinal metaplasia: a comparison of traditional mucin staining with immunohistochemistry for the sulfo-Lewis(a) carbohydrate epitope

BACKGROUND

Premalignant Barrett's oesophagus (BO) and gastric intestinal metaplasia (IM) show phenotypic variability. Incompletely differentiated sulfomucin rich gastric IM (type III) may have increased malignant potential. The types of sulfated oligosaccharide structures present in IM, BO, and colon have not been fully characterised.

AIMS

To compare sulfo-Lewis(a) epitope tissue distribution with high iron diamine (HID) positive sulfomucin in metaplastic, dysplastic, and neoplastic tissues from oesophagus and stomach.

METHODS

Sections containing gastric IM or BO (some associated with dysplasia or adenocarcinoma) were stained by the HID/alcian blue (AB) method and immunohistochemically (antibody 91.9H) to detect sulfo-Lewis(a). Based on HID/AB staining, IM was subtyped into type I (complete) or types II and III (incomplete).

RESULTS

In total, 125 sections from 38 subjects were studied. Normal squamous oesophagus, normal gastric epithelium, and type I IM were negative for sulfomucin and sulfo-Lewis(a). In type II IM, occasional goblet cells were HID and sulfo-Lewis(a) positive, but sialomucin secreting (AB positive) columnar cells were sulfo-Lewis(a) negative. Type III IM was always sulfo-Lewis(a) positive. Sulfomucin staining in dysplasia and cancer was variable, but HID positive areas were always sulfo-Lewis(a) positive.

CONCLUSIONS

Sulfo-Le(a), which is expressed on colonic mucin, is invariably present on sulfomucins in gastric IM and BO. Its presence in incomplete variants of IM and its absence from type I IM emphasises the phenotypic differences between complete and incomplete forms of metaplasia. 91.9H immunostaining is useful in IM subtyping. Characterising the molecular basis of sulfo-Lewis(a) expression may help understand the process of aberrant differentiation.

Expression of apoptosis-related proteins in Barrett's metaplasia-dysplasia-carcinoma sequence: a switch to a more resistant phenotype

Barrett's esophagus, or columnar-lined esophagus (CLE), is a premalignant disorder in which the stratified squamous epithelium is replaced by metaplastic epithelium. To gain more insight into the process of carcinogenesis in CLE, we studied several factors involved in the apoptotic pathway in biopsies with gastric metaplasia (GM), intestinal metaplasia (IM), dysplasia, and/or adenocarcinoma. Immunohistochemistry was performed for Fas, Bcl-2, Bax, Bcl-xl, inducible nitric oxide synthase (iNOS), and cyclooxygenase 2 (COX-2). Fas staining was positive in the epithelium of all biopsies from patients with CLE but negative in normal gastric mucosa. Fas staining was positive in all tumor cells of the 8 cases containing adenocarcinoma. Bcl-2 was positive in lamina propria immune cells of all specimens. Bax staining was positive in the epithelium of all biopsies, including tumor cells. Bcl-xl was positive in dysplasia and tumor cells, but negative in 8 of 17 biopsies containing IM. iNOS was positive in 20 of 21 biopsies with IM and in 4 of 8 dysplasia biopsies. COX-2 was positive in 7 of 8 adenocarcinomas. We conclude that the apoptotic balance in the transformation from IM to adenocarcinoma switches to an antiapoptotic phenotype because of increased Bcl-xl expression and decreased Bax expression. Fas can be used as a marker for the differentiation of gastric mucosa and metaplasia in the esophagus. iNOS is highly positive in CLE-associated intestinal metaplasia. COX-2 is negative in nonmalignant CLE. Therefore, pharmacologic inhibition of COX-2 activity is unlikely to be effective in the preventing CLE-associated adenocarcinoma. There was no clear correlation between iNOS expression and activation of proapoptotic and antiapoptotic genes.

Cytokeratin immunoreactivity of intestinal metaplasia at normal oesophagogastric junction indicates its aetiology

BACKGROUND AND AIMS

Cytokeratin (CK) 7 and 20 patterns are specific for long and short segments of Barrett's oesophagus but their use has not been assessed in intestinal metaplasia arising in macroscopically normal gastro-oesophageal junction (GOJ).

PATIENTS AND METHODS

This study was carried out in a large prospective series of 254 patients who underwent upper endoscopy, had normal gastro-oesophageal anatomy, and who had biopsies of the antrum, fundus, cardia, GOJ, and lower oesophagus. Intestinal metaplasia of the GOJ was typed by histochemistry with high iron diamine-alcian blue staining and by immunohistochemistry using CK7 and CK20 antibodies. Results were correlated with clinical, endoscopic, and pathological data.

RESULTS

Sixty (23.6%) of our patients presenting with a normal GOJ had intestinal metaplasia. The CK7/CK20 pattern identified two groups of patients: one highly correlated with Barrett's and the other with characteristics of Helicobacter pylori gastritis. The Barrett's type CK7/CK20 pattern was related to a high frequency of gastro-oesophageal reflux symptoms (p<0.02) and normal endoscopic appearance of the stomach (p<0.03). In contrast, the gastric type CK7/CK20 pattern was linked to atrophic (p<0.02) or erythematous (p<0.05) appearance of the stomach (p<0.03), high frequency of H pylori infection (p<0.04), antral inflammation (p<0.006) with atrophy (p<0.02), and intestinal metaplasia (p<0.02).

CONCLUSION

In patients presenting with intestinal metaplasia in normal appearing GOJ, the cytokeratin pattern identifies two groups of patients, one with features identical to those of long segment Barrett's oesophagus and one with features seen in H pylori gastritis. These data may be used by clinicians and should result in improved endoscopic surveillance strategies targeted specifically at patients at increased risk of Barrett's oesophagus and thus cancer.

Mucin gene expression in Barrett's oesophagus: an in situ hybridisation and immunohistochemical study

BACKGROUND AND AIMS

Mucin genes are expressed in a site specific manner throughout the gastrointestinal tract. Little is known about the expression pattern in the oesophagus. In this study we have investigated MUC gene expression in both the normal oesophagus and specialised intestinal metaplasia (Barrett's oesophagus).

PATIENTS

Archived paraffin embedded material from eight specimens of normal oesophagus, 18 Barrett's oesophagus, eight gastric metaplasia, six high grade dysplasia, and six cases of adenocarcinoma were examined for expression of the mucin genes MUC1-6.

METHODS

Mucin mRNA was detected by in situ hybridisation using [(35)S] dATP labelled oligonucleotide probes. Mucin core protein was detected by immunohistochemistry.

RESULTS

Normal oesophagus expressed MUC5B in the submucosal glands and MUC1 and MUC4 in the stratified squamous epithelium. Barrett's oesophagus strongly expressed MUC5AC and MUC3 in the superficial columnar epithelium, MUC2 in the goblet cells, and MUC6 in the glands. In high grade dysplasia and adenocarcinoma there was downregulation of MUC2, MUC3, MUC5AC, and MUC6, but upregulation of MUC1 and MUC4 in half of the specimens examined.

CONCLUSIONS

Normal oesophagus and Barrett's oesophagus have a novel pattern of mucin gene expression. Barrett's oesophagus expressed the mucins associated with normal gastric epithelium and normal intestinal epithelium. While most mucin genes were downregulated in severely dysplastic and neoplastic tissues, there was upregulation of the membrane bound mucins MUC1 and MUC4. This may prove useful in detecting early signs of progression to adenocarcinoma of the oesophagus.

Patterns of gastritis in patients with gastro-oesophageal reflux disease

BACKGROUND

The cause of inflammation in cardiac mucosa at the gastro-oesophageal junction (GOJ) is unclear, both gastro-oesophageal reflux disease (GORD) and Helicobacter pylori having been implicated.

AIMS

To describe patterns of gastritis in patients with symptomatic GORD.

METHODS

In 150 patients (126 normally located Z-line, 24 Barrett's oesophagus) with symptoms of GORD, biopsies were taken of the GOJ, corpus, and antrum. Inflammation was assessed using the updated Sydney System.

RESULTS

For the 126 patients with a normally located Z-line, biopsies of the GOJ revealed cardiac mucosa in 96, fundic mucosa in 29, and squamous mucosa in one. Inflammation in glandular mucosa at the GOJ was present in 99/125 specimens (79%), including 87/96 (91%) with cardiac mucosa and 12/29 (41%) with fundic mucosa. Inflammation in fundic mucosa was closely related to H pylori and active inflammation was only seen in its presence. Inflammation in cardiac mucosa was less closely linked to H pylori. When H pylori was present in cardiac mucosa (28/96, 29%) active inflammation was usually present (25/28, 89%). However, active inflammation was also found in 34/68 (50%) cardiac mucosa specimens without H pylori. Overall, 28/87 (32%) biopsies with carditis were colonised with H pylori and 59/87 (68%) were not. In H pylori colonised patients, inflammation was seen throughout the stomach, while in non-colonised patients, it was confined to cardiac mucosa.

CONCLUSIONS

Patients with symptomatic GORD had a high prevalence of carditis. This was of two types, H pylori associated and unassociated. Except on Giemsa staining, the two were morphologically identical, suggesting mediation by a similar immunological mechanism.

Barrett's esophagus: the long and the short of it

Specialized intestinal epithelium occurs more frequently at the gastroesophageal junction than previously anticipated. It can occur either within tongues of mucosa (short segment Barrett's) or just beneath a normal z-line (intestinal metaplasia at the gastroesophageal junction). Whether the etiopathogenesis and the natural history of these two conditions are the same is as yet unclear. The role of gastroesophageal reflux disease (GERD), Helicobacter pylori, and inflammation at the gastroesophageal junction in the pathogenesis of short segment Barrett's and intestinal metaplasia at the gastroesophageal junction needs to be carefully documented. Intestinal metaplasia at the gastroesophageal junction, short segment Barrett's, and Barrett's may represent a continuum of the same disease process. Recent evidence suggests, however, that short segment Barrett's shares similar characteristics with Barrett's but may be distinct from intestinal metaplasia at the gastroesophageal junction. It is conceivable that short segment Barrett's may remain steady or even regress if and when the noxious influence wanes but, with continuing stimulation, short segment Barrett's may lengthen further to become what we observe to be Barrett's. If correct, endogenous or exogenous factors that induce progression need to be identified. Acid and bile reflux and H. pylori are possible candidates acting either singly or synergistically. Finally, the true neoplastic potential of short segment Barrett's needs clarification.

Short segment Barrett's oesophagus: prevalence, diagnosis and associations

BACKGROUND

Prevalence of short segment Barrett's (SSB) oesophagus, defined as the absence of macroscopic Barrett's but histologically identifiable intestinal metaplasia, has been reported to be 18% based on haematoxylin and eosin (H&E) staining.

AIMS

To define the prevalence of SSB oesophagus using H&E and alcian blue staining and to determine whether SSB oesophagus is associated with inflammation at the gastro-oesophageal junction (GOJ).

SUBJECTS

Consecutive patients (n = 158) presenting for endoscopy completed a structured interview.

METHODS

Two biopsy specimens taken from the GOJ were stained with H&E, alcian blue and Giemsa. A third specimen was obtained from the distal oesophagus. Intestinal metaplasia was diagnosed if goblet cells were definitely identified by two independent observers.

RESULTS

SSB oesophagus was present in 46 (prevalence 36%, 95% confidence interval (CI) 28.5-43.5) using alcian blue staining. If H&E had been the sole staining method used, 50% cases of intestinal metaplasia would have been overlooked. There were no cases of intestinal metaplasia identified by H&E but missed by alcian blue staining. Logistic regression analysis identified age (odds ratio (OR) per decade 1.03, 95% CI 1.01-1.06), histological oesophagitis (OR 3.2, 95% CI 1.4-7.2) and inflammation at the gastrooesophageal junction (OR 5.9, 95% CI 2.2-15.6) as independent risk factors for SSB oesophagus.

CONCLUSION

Unrecognised SSB oesophagus is highly prevalent in patients presenting for diagnostic upper endoscopy if alcian blue staining is applied.

Metaplastic columnar cells in Barrett's esophagus: a common and neglected cell type

Goblet cells are considered by most to be a prerequisite for the diagnosis of Barrett's esophagus. Columnar cells that are alcian blue (AB) positive (as are goblet cells) are commonly observed in the surface epithelium of Barrett's esophagus, but their distribution in relation to goblet cells has not previously been defined. The authors analyzed the prevalence and distribution of these cell types in the surface but not pit epithelium (where they may sometimes be present in normal gastric mucosa). The distribution of the AB-positive columnar cells was mapped out in the entire mucosa of nine esophagectomy specimens, resected for Barrett's-associated high-grade dysplasia or carcinoma, and compared with other cell types, especially goblet cells. AB-positive goblet and columnar cells were present in 87.1% +/- 5.6% and 85.7% +/- 5.9%, respectively, of the evaluated sections of Barrett's mucosa, whereas gastric-type, AB-negative cells were observed in 46.3% +/- 8.7% of the sections. In 53% of the sections, the surface epithelium contained more than 25% AB-positive cells, and in more than three quarters of these sections, AB-positive columnar cells were the dominant AB-positive cell type. No difference in the distribution of the AB-positive epithelial cells was noticed between the proximal and distal halves of the Barrett's mucosae. In the cardia region, seven of nine cases showed a few scattered AB-positive columnar cells, and five of nine cases showed a few scattered goblet cells. No AB-positive cells were found in fundic gland mucosa. These findings indicate that the metaplastic AB-positive columnar cells are more prevalent than goblet cells. They may be analogous to incomplete metaplastic cells of the stomach, and, therefore, their role in the development of neoplasia needs further study.

Scanning electron microscopy of the human esophagus: application to Barrett's esophagus, a precancerous lesion

In Barrett's esophagus, metaplastic columnar epithelium replaces the normal squamous epithelium. The importance of this lesion lies in the increased incidence of adenocarcinoma of the esophagus occurring in patients with Barrett's esophagus. We characterized the surface epithelial cells of Barrett's esophagus using quantitative scanning electron microscopy. Three distinct surface cell types, in addition to the globlet cell, were recognized in Barrett's epithelium: the gastric-like cell and the intestinal-like cell, both of which were similar to normal gastric and small intestinal surface cells, respectively, by quantitative scanning electron microscopy, and the variant cell which had a range of surface features. In four biopsy specimens from the squamo-Barrett's junction in three patients, we found the distinctive cell that had features intermediate between those of squamous and columnar epithelium. On the distinctive cell's surface there are two disparate structures not normally present on the same cell in the gastrointestinal tract: microvilli (a scanning electron microscopy feature of glandular epithelium) and intercellular ridges (a scanning electron microscopy feature of squamous epithelium). The surface characteristics of this cell were almost identical to those of cells found in the transformation zone of the uterine cervix, an area in which squamous epithelium physiologically replaces columnar epithelium. Scanning electron microscopy of Barrett's esophagus has increased our understanding of this precancerous lesion by showing striking cellular heterogeneity. It has also identified the distinctive cell which may represent an intermediate step in the development of Barrett's epithelium during which the surface characteristics of two different cell types, columnar and squamous, coexist in the same cell.

Barrett's esophagus, dysplasia, and adenocarcinoma

In Barrett's esophagus the normal stratified squamous epithelium lining the esophagus becomes replaced by metaplastic columnar epithelium containing goblet cells; it develops as a complication of chronic gastroesophageal reflux disease and predisposes the patient to adenocarcinoma. The frequency with which it leads to adenocarcinoma is not established with certainty, but the reported prevalence averages approximately 10% when the diagnosis of Barrett's esophagus is first made. The estimated incidence of adenocarcinoma varies from one in 152 to one in 441 cases per patient year, or a 30- to 125-fold excess risk. Esophageal adenocarcinoma arises only in patients with metaplastic columnar epithelium. Dysplasia precedes adenocarcinoma in Barrett's esophagus and arises from the metaplastic epithelium; it has been proposed as a marker for detecting patients at high risk for developing carcinoma. Problems with the use of dysplasia as a marker for cancer risk include difficulty in differentiating it from reactive change, variability in diagnosis and grading between observers and when the same observer interprets the sections on different occasions, and lack of understanding of its natural history. Methods other than dysplasia for detecting patients at highest risk for developing carcinoma have been sought, but flow cytometric analysis of DNA content is the only one proven to be valuable to date. Flow cytometric abnormalities correlate well with histological progression in Barrett's esophagus. The prevalence of elevated S phase and G2/tetraploid fractions and of aneuploid cell populations increases with histological progression from metaplasia to indefinite/low grade dysplasia to high grade dysplasia and cancer. Flow cytometric abnormalities in endoscopic biopsy specimens identify those patients with a higher risk of progression to high grade dysplasia or adenocarcinoma.

Diagnostic inconsistencies in Barrett's esophagus. Department of Veterans Affairs Gastroesophageal Reflux Study Group

BACKGROUND/AIMS

Few studies have compared the precision of various diagnostic tests used to determine the presence of Barrett's esophagus. The aim of this study was to compare the results of histological, endoscopic, and manometric tests for patients with Barrett's esophagus in two closely spaced examinations.

METHODS

In a Veterans Administration Cooperative Study, 192 patients with complicated gastroesophageal reflux disease had esophageal manometry and endoscopy performed at baseline and after 6 weeks. At each examination, the endoscopist localized the most proximal level of Barrett's epithelium and the lower esophageal sphincter and obtained esophageal biopsy specimens.

RESULTS

One hundred sixteen patients met the criteria for Barrett's esophagus on at least one of the two endoscopic examinations. Among patients with specialized columnar epithelium, 20% had specialized columnar epithelium found on only one of the two examinations. Although the mean lower esophageal sphincter level did not change, approximately 10% of patients had a change > or = 4 cm on endoscopy and manometry between examinations. This led to an apparent change in the diagnosis in 18% of patients with Barrett's esophagus.

CONCLUSIONS

From one endoscopic examination to another, inconsistencies in the ability to detect specialized columnar epithelium are common. This may lead to substantial problems in establishing an accurate diagnosis of Barrett's esophagus.

Barrett's disease: pathophysiology of metaplasia and adenocarcinoma

Peptic ulceration arising in the lower esophagus lined by columnar epithelium was described in detail by Tileston in 1906. Although this concept was challenged in 1950 by Barrett, experimental and clinical evidence has now conclusively demonstrated that Barrett's metaplasia is an acquired condition and is a consequence of chronic reflux of gastric or duodenal contents or both. Current concepts suggest that unknown trophic factors present in these secretions stimulate proliferation of multipotential reserve cells located in the esophageal submucosal glands resulting in columnar metaplasia of the normal squamous epithelium with subsequent potential for malignant degeneration. Today, numerous patients are affected by reflux esophagitis, a lesser number by Barrett's metaplasia, and a smaller but ever-enlarging group by adenocarcinoma. Although high-grade dysplasia is considered a precursor to invasive adenocarcinoma, detection of this abnormal mucosa remains controversial and currently requires esophagoscopy with biopsy. Epithelial markers, such as increased activity of mucosal ornithine decarboxylase, sulfomucin production, nuclear DNA aneuploidy, and recently molecular analysis, have also been proposed to identify those paitents at increased risk for malignant degeneration. As more is learned about the pathogenesis of Barrett's disease, perhaps these cancers can ultimately be prevented.

Transitional cell carcinoma pattern in primary carcinoma of the fallopian tube

BACKGROUND

A broad papillary proliferation resembling that in transitional cell carcinoma (TCC) of the urinary bladder was seen in 12 of 21 primary carcinomas of the Fallopian tube (PCFT).

METHODS

According to their predominant histologic pattern (more than 50%), PCFT were classified into 9 TCC-predominant and 12 non-TCC-predominant tumors. The two groups were compared by clinicopathologic, histochemical, and immunohistochemical means.

RESULTS

TCC-predominant tumors were grossly solid and microscopically demonstrated more frequent tumor necrosis and spindled tumor cells than non-TCC-predominant tumors. Mucin histochemistry revealed a correlation between TCC-predominant tumor and sulfomucin-predominant secretion and between non-TCC-predominant tumor and sialomucin-predominant secretion. Immunohistochemical studies for cytokeratins, vimentin, epithelial membrane antigen (EMA), Leu-M1, carcinoembryonic antigen (CEA), and CA 125 were not useful for discrimination between the two groups. Both groups showed similar features in patient age, clinical stage, cytology of ascites or peritoneal washing, and serum CA 125 level. Despite the similarity in treatment (surgery and postoperative chemotherapy) between the two groups, TCC-predominant tumors tended to relapse later (mean, 31.2 months after diagnosis) than non-TCC-predominant tumors (mean, 14.4 months after diagnosis), resulting in a significant difference in the 2-year disease-free survival rate.

CONCLUSIONS

TCC pattern and non-TCC pattern are considered to be worthy of distinction in PCFT.

Epithelial proliferation in Barrett's esophagus by proliferating cell nuclear antigen immunolocalization

Proliferating cell nuclear antigen (PCNA) is an auxiliary protein to DNA polymerase delta and is an absolute requirement for cellular proliferation. Specialized-type Barrett's columnar-lined esophagus (CLE) is associated with adenocarcinomatous change. In the present study, the cellular proliferation of three histological types of CLE was assessed by semiquantitative evaluation of PCNA immunolocalization in 93 biopsy specimens from 45 patients using the murine monoclonal PC10. Statistical comparison was performed by the Mann-Whitney U test. Luminal surface cell labeling was uncommon in all histological types other than specialized CLE where 25 of the 43 biopsy specimens had at least occasional luminal surface cell labeling. Mean crypt labeling score of 4.06 for specialized type exceeded that for junctional (mean, 3.12; P < 0.001) and fundic types (mean, 1.6; P < 0.001). Gland cell PCNA staining scores for specialized-type CLE (mean, 3.18) exceeded that of junctional (mean, 1.97; P < 0.001) and fundic (mean, 1.04; P < 0.001). Summated PCNA scores for specialized-type, mean of 8.29, exceeded junctional mean score of 5.45 (P < 0.001) and fundic mean score of 2.76 (P < 0.001). PCNA immunolocalization reveals a high proportion of cells in cycle in the specialized-type CLE and expansion of the proliferative compartment, which may explain the association of specialized-type CLE with malignancy.

Blood group-related antigen expression in normal and metaplastic human upper gastrointestinal mucosa

Lewis antigen expression in upper gastrointestinal epithelium was studied using four monoclonal antibodies to determine the relationship between aberrant differentiation and antigen expression. Specific patterns of type 1 and type 2 Lewis blood group antigen expression were found in the surface and glands of the esophagus, gastric fundus, and duodenum. In biopsy specimens of Barrett's esophagus, gastric fundic-type columnar metaplasia expressed Lewis antigens indistinguishable from those in the normal stomach. In Barrett's junctional and specialized columnar metaplasia, Lewis a antigen was aberrantly expressed on the surface in secretors and in the glands independent of secretor state. Lewis x reactivity was markedly diminished in the glands of Barrett's junctional and specialized columnar epithelium irrespective of secretor state. There was no significant aberrancy observed in the expression of Lewis b and y antigens. The observed aberrant expression of Lewis antigens may be caused by an altered differentiation program in Barrett's metaplastic epithelium and may define a role for these glycoconjugates in the process of metaplasia and carcinogenesis in Barrett's epithelium.

Predominance of sialomucin secretion in malignant and premalignant pancreatic lesions

Sialomucin and sulphomucin-secreting cells were studied in the normal and pathologic human pancreas with the high iron diamine-alcian blue technique which allows differentiation between the two types of mucin. In six normal autopsy pancreata, only sulphomucin was found. In benign lesions of either calcifying chronic pancreatitis (seven cases) or obstructed chronic pancreatitis (six cases), sulphomucins were widely predominant. In contrast, malignant lesions (pancreatic adenocarcinoma [12 cases], cystadenocarcinoma [two cases]) or premalignant lesions (mucinous cystadenoma [one case], ductectatic mucinous cystadenoma [four cases], villous adenoma of the main pancreatic duct [two cases]) showed a predominant sialomucin secretion, except for three poorly differentiated pancreatic carcinomas that did not show mucin staining. The sialomucin positivity was not observed at distance from the malignant lesions. In one case of benign enteroid cyst, sulphomucins predominated. These findings indicate a preponderance of sialomucin secretion in malignant or premalignant pancreatic lesions.

Superficial adenocarcinoma of the oesophagus arising in Barrett's mucosa with dysplasia: a clinico-pathological study of 12 patients

Superficial adenocarcinoma of the oesophagus is defined as carcinoma limited to the mucosa or submucosa regardless of lymph node status. Columnar epithelium lined lower oesophagus, now generally referred to as Barrett's oesophagus, is probably the main cause of adenocarcinoma in the lower oesophagus. Twelve cases of superficial adenocarcinoma arising in Barrett's oesophagus are presented. They were observed over a 6 year period and taken from a series of 50 cases of patients with Barrett's oesophagus and adenocarcinoma, a prevalence of 24%. Endoscopic diagnosis of malignancy was made in six patients. The initial biopsies showed an adenocarcinoma in six patients and some degrees of dysplasia in the other six patients. Prior to surgery, a histological diagnosis of adenocarcinoma was made in all twelve patients. In four patients the adenocarcinoma was confined to the mucosa, and in eight it extended to the submucosa. One patient had a metastatic lymph node. Ten patients are alive without evidence of tumour spread after a mean follow-up of 30 months.

Value of DNA image cytometry in the prediction of malignant change in Barrett's oesophagus

DNA image cytometry was performed on Feulgen stained sections from 91 biopsies obtained during prospective endoscopic surveillance of 55 patients with Barrett's oesophagus. Aneuploid cells were detected in specimens from six of these patients. Four subsequently developed dysplasia and adenocarcinoma but, in the other two, biopsies had been reported as showing specialised epithelium only, with no apparent dysplasia and no evidence of malignancy on clinical follow up to date. In two of the four patients who subsequently developed carcinoma, aneuploid cells were only found in biopsies showing overt dysplasia or carcinoma but in the two other patients aneuploid cells were present in biopsies taken early in the clinical course before any dysplasia had been identified on the original reports. The presence of aneuploid cells on cytometry of these 'benign' biopsies allowed us, on histological review, to identify areas of atypia which were interpreted as mild dysplasia. In this series aneuploidy was always associated with some morphological abnormality varying from mild dysplasia to frank carcinoma. Aneuploid cells were not shown in material from one patient who had an oesophagectomy for dysplasia or in biopsy material from four patients showing 'indefinite dysplasia'. DNA cytometry combines an objective assessment of epithelial atypia with the advantage of detecting rare cellular aneuploidy and the ability to correlate these events with morphology. It should assist in the more accurate diagnosis of dysplasia and prove useful in identifying those patients with Barrett's oesophagus who are at greater risk of subsequently developing malignancy.

Mucin immunohistochemistry of the columnar epithelium of the oesophagus (Barrett's oesophagus)

Columnar cell lined lower oesophagus (CELLO), often considered to be a precancerous lesion, is characterized by a glandular mucosa with a predominance of sulphomucins in the specialized epithelium. This histochemical abnormality can be correlated with abnormal differentiation which may also be studied by anti-mucus antibodies (anti-M1, anti-M3, anti-SIMA, anti-LIMA). The purpose of this prospective study is to define the mucin profile in a large population of CELLO by immunohistochemistry and to compare it with the results of histochemistry. Biopsies of 79 patients with reflux oesophagitis were included. Thirty-eight had CELLO and 41 had a histologically normal cardia. Six surgical specimens of oesophageal adenocarcinomas were also included. The histochemical methods confirmed the preponderance (57.9%) of type III intestinal metaplasia (IM) found in 57.9% of cases. The immunohistochemical methods showed a similar antigenic profile of type II and III IM with positivity of anti-SIMA and anti-M3 antibodies in the goblet cells, and positivity of anti-LIMA antibodies in both the goblet and intermediate cells of the specialized epithelium. The mucus secreting cells of the oesophageal adenocarcinomas had the same immunohistochemical profile. These results are similar to those of Filipe et al. in type II and III IM surrounding gastric adenocarcinomas. Immunohistochemical methods allow us to subdivide type II and type III IM into 2 subgroups according to the positivity or negativity of the anti-LIMA antibodies in the intermediate cells. Among the 41 normal cardias in patients with reflux oesophagitis, 10 contain sulphomucin secreting cells positive with anti-LIMA antibodies. We suggest that this anti-LIMA positivity may be a step preceding type III IM in specialized epithelium.

Campylobacter pylori and Barrett's esophagus

Occurrence of C. pylori infection of mucosa outside of the stomach might provide an ideal opportunity to examine C. pylori-mucosal interactions apart from the effects of acid and pepsin. Techniques previously used to examine Barrett's epithelium (for example, special mucin stains or scanning and transmission electron microscopy) might be particularly useful for exploration of new associations and formulation of new hypotheses. Whether C. pylori has a role in development of Barrett's ulcer or adenocarcinoma as a complication of Barrett's esophagus remains unanswered. Most of the current data about C. pylori are primarily observational; further studies are needed for clarification of important microbegut interactions.

Mucin histochemistry of heterotopic gastric mucosa of the upper esophagus in adults: possible pathogenic implications

The mucin profile of 24 endoscopic biopsies of heterotopic gastric mucosa (HGM) of the upper esophagus in adults and a control group of ten cases of Meckel's diverticula containing heterotopic gastric mucosa were studied with two combined histochemical methods: alcian blue pH 2.5/PAS and high iron diamine/alcian blue pH 2.5. The clinical and light microscopic features of the 24 HGM cases were also reviewed. In addition to overall secretion of neutral mucins by the 24 HGM cases, mucin histochemistry showed prominent secretion of acidic mucins in 19 of 24 HGM cases (79%), with sulphomucins in 11 of 24 HGM cases (45.8%). This mucin profile of HGM was unlike that of either normal gastric mucosa or heterotopic gastric mucosa in Meckel's diverticula. Moreover, a comparison between the mucin profile and clinical features of HGM and Barrett's esophagus showed certain similarities. The data suggest a physiopathologic link between HGM and Barrett's esophagus.

Value of endoscopic surveillance in the detection of neoplastic change in Barrett's oesophagus

Fifty-six patients with Barrett's oesophagus diagnosed between 1977 and 1986 were prospectively studied by 6-monthly endoscopic surveillance and biopsy. During follow-up to-date, four patients have developed high-grade dysplasia and three have adenocarcinoma of the oesophagus. Two of the adenocarcinomas were preceded by progressively severe dysplastic changes but in the third no dysplasia had been previously detected. The incidence of adenocarcinoma was 1 per 56 patient-years of follow-up. Changes in symptomatology or gross endoscopic appearances were usually absent, even after adenocarcinoma had developed, indicating that biopsy is essential for early diagnosis. The high risk of malignant change makes endoscopic surveillance advisable in all patients with Barrett's oesophagus.

Barrett's esophagus. Correlation between mucin histochemistry, flow cytometry, and histologic diagnosis for predicting increased cancer risk

A predominance of sulfated mucin in the nongoblet columnar cells of Barrett's specialized metaplastic epithelium has been postulated to be a form of mild dysplasia and to indicate an increased risk of adenocarcinoma. Flow cytometry for the analysis of nuclear DNA content and cell cycle parameters has also been postulated to be an objective aid in the diagnosis of dysplasia and carcinoma in Barrett's esophagus. The authors investigated the relationship among sulfated mucin, flow cytometric data, and histologic diagnosis in each of 152 biopsies from 42 patients who had Barrett's specialized metaplastic epithelium. Sulfated mucin, as detected by the high iron diamine-Alcian blue stain, was present in biopsies from 8 of 11 (73%) patients with the histologic diagnosis of dysplasia or carcinoma, in 7 of 9 (78%) patients whose biopsies were indefinite for dysplasia, and in 12 of 22 (55%) patients whose biopsies were negative for dysplasia (P = 0.37). Sulfated mucins predominated in 9%, 22%, and 9% of the patients, respectively (P = 0.56). Abnormal flow cytometry (aneuploidy or increased G2/tetraploid fraction) was found in all patients with the histologic diagnosis of dysplasia or carcinoma, in 3 of 9 (33%) indefinite for dysplasia, and in 1 of 22 (5%) negative for dysplasia (P = less than 0.0001). Neither the presence nor the predominance of sulfated mucin in the specialized metaplastic epithelium of Barrett's esophagus has sufficiently high sensitivity or specificity for dysplasia or carcinoma to be of value in managing patients. Abnormal flow cytometry shows excellent correlation with the histologic diagnosis of dysplasia and carcinoma; it detects a subset of patients whose biopsies are histologically indefinite or negative for dysplasia, but who have flow cytometric abnormalities similar to those otherwise seen only in dysplasia and carcinoma.

Glycoconjugate expression in normal, metaplastic, and neoplastic human upper gastrointestinal mucosa

Glycoconjugate structure in upper gastrointestinal epithelium was studied using five lectins to determine the relationship between aberrant differentiation and glycoconjugate expression. Specimens of normal esophagus, stomach, and duodenum were examined and compared with specimens of columnar metaplasia in the esophagus (Barrett's esophagus) and specimens of adenocarcinoma of the esophagus and stomach. Specific terminal glycoconjugate structures were found for the esophagus, stomach, and duodenum. Minor differences were found between the antral and fundic gland mucosae, reflecting their respective cell populations. In biopsies of Barrett's esophagus, gastric-type columnar metaplasia expressed glycoconjugates indistinguishable from those in the normal stomach. In specialized-type columnar metaplasia, a more restricted expression of glycoconjugates was seen resembling the normal duodenum. The presence of low grade dysplasia in Barrett's esophagus associated with adenocarcinoma had no impact on glycoconjugate expression. However, a distinctive difference in glycosylation was seen in high grade dysplasia of the columnar-lined esophagus and in adenocarcinoma of the esophagus and stomach. Barrett's esophagus is a morphological mosaic in which the glycoconjugate expression resembles that seen in the normal stomach and duodenum. However, in high grade dysplasia and carcinoma, variable deletion of glycoconjugate expression can be found.

Barrett's esophagus in children: a histologic and histochemical study of 11 cases

Columnar epithelium-lined esophagus is an acquired phenomenon arising secondarily to chronic mucosal injury from gastroesophageal reflux. This report documents 11 children with complications of reflux and the histologic finding of gastric mucosa in the esophagus. Five children had strictures, one requiring esophageal replacement and four treated by antireflux surgery followed by sleeve-resection of a short fibrotic stricture. Specimens from two patients showed mild dysplasia and from six others slight nuclear atypia. Intestinal metaplasia was apparent in one case on routine histology and was revealed in six other cases by mucin histochemical strains. The significance of the histopathologic findings is discussed in the context of possible malignant potential.

Histological and histochemical changes in the columnar lined (Barrett's) oesophagus

Multiple endoscopic specimens were obtained from 58 patients with a columnar lined gesophagus to study the histological and histochemical features of this metaplastic epithelium. Five patients (8.6%) had presented with a primary oesophageal adenocarcinoma. Three different epithelial types, junctional, atrophic fundic and intestinal were identified. Twenty two (38%) patients had just one type of epithelium present, the other 36 (62%) having a combination of two or three different types. Intestinal type of epithelium, either alone or in combination with gastric type epithelium was present in 48 (83%) patients. In every case this intestinal type epithelium took the form of an incompletely differentiated variant of intestinal metaplasia, although complete intestinal metaplasia as a focal change was also present in 14 of these patients. Histochemically, sulphomucins were present in the biopsies of 43 (74%) of the patients studied. They were seen in both goblet and columnar mucous cells with almost equal frequency. Incomplete intestinal metaplasia with sulphomucin production was present in four of the five patients with an oesophageal adenocarcinoma. In the columnar lined oesophagus sulphomucin production is common and its presence does not help to identify those individuals at particular risk of developing an adenocarcinoma.