Distribution and significance of epithelial types in columnar-lined esophagus

Gastric and intestinal differentiation in Barrett's metaplasia and associated adenocarcinoma

Intestinal metaplasia is a prerequisite criterion for the diagnosis of Barrett's metaplasia and the sole columnar esophageal lining associated with malignancy. It is recognized by the presence of goblet cells, but columnar non-goblet elements, producing gastric or intestinal proteins, are the prevalent cell population. The cellular heterogeneity of Barrett's metaplasia is well documented but the relationship between the distinct cell subtypes and neoplasia is unclear. Our aim was to clarify the relationship between the different metaplastic populations and malignancy in order to investigate putative markers for risk stratification of Barrett's patients. We studied 46 columnar-lined esophageal segments, 15 with associated adenocarcinoma. The presence of the gastric, MUC5AC and MUC6, and the intestinal, MUC2, proteins was evaluated in metaplastic (columnar and goblet) and neoplastic cells. In neoplasia MUC5AC and MUC6 were detected in 100% and 86.6% of the cases, respectively. In metaplasia there were no differences in MUC5AC and MUC6 immunoreactivity, between cases with and without associated neoplasia, except for goblet elements producing MUC6 that were exclusive of metaplasia adjacent to adenocarcinoma (P < 0.05). MUC2 was present in 86.6% of the neoplasia. In metaplasia it was restricted to Barrett's cases and was more frequent in areas with intestinal metaplasia. Columnar-lined esophagus without intestinal metaplasia did not express MUC2. Our study suggests a relationship between the metaplastic population with gastric phenotype and malignancy, and points to the involvement of columnar as well as goblet elements in tumorigenesis. The association between goblet cells aberrantly producing MUC6 and the presence of neoplasia suggests they may be useful for risk stratification.

Prospective analysis of patients with adenocarcinoma of the gastric cardia and lymph node metastasis in the proximal field of the chest

BACKGROUND

The extent to which adenocarcinoma of the cardia with lymph node metastasis in the upper mediastinum is amenable to cure by radical surgery is open to debate. It remains unclear whether these relatively distant metastases have an effect on long-term survival. The aim of this study was to identify the incidence of such positive nodes and evaluate their prognostic significance.

METHODS

Some 50 patients with adenocarcinoma of the gastric cardia and substantial invasion of the oesophagus (junctional type II), who underwent an extended transthoracic oesophagectomy as part of a prospective randomized trial between 1994 and 2000, were studied.

RESULTS

Eleven patients (22 per cent) had lymph node metastasis in the proximal field of the chest. These patients had more positive nodes overall (P = 0.020) and a shorter median survival (P = 0.009) than those without such metastasis. Multivariate analysis identified positive nodes in the proximal field as an independent predictor of poor survival.

CONCLUSION

Lymph node metastasis in the proximal field of the chest is common and is an indicator of poor prognosis in patients with adenocarcinoma of the cardia.

Small-bowel metaplasia arising in the remnant esophagus after esophagojejunostomy--a [corrected] prospective study in patients with a history of total gastrectomy

OBJECTIVES

The pathogenesis of Barrett's mucosa is incompletely understood. Acidic gastro-esophageal reflux is considered an essential causative factor. The aim of this study was to detect esophageal columnar metaplasia after total gastrectomy with esophagojejunostomy, a condition of enteric, but nonacidic reflux.

METHODS

In a prospective study, patients with a history of total gastrectomy and esophagojejunostomy were investigated for the presence of columnar metaplasia in the remnant esophagus. Patients with such history, who were now referred for esophagogastroduodenoscopy, were included during a 2-yr period. Biopsies for histopathology were taken from the anastomosis and any columnar metaplasia of the esophagus.

RESULTS

In 8 of 25 patients (32%) with a history of gastrectomy, columnar metaplasia was found in the remnant esophagus, mostly in shape of tongues, partly associated with erosive reflux esophagitis. Histopathology showed a typical small-bowel mucosa, but with some villous atrophy. In a resection specimen, a double-layered muscularis mucosa was present, which proved the metaplastic nature of the intestinal mucosa. Length of the columnar metaplasia correlated with the time interval since surgery.

CONCLUSIONS

Esophageal mucosa, if exposed long term to an enteric, but nongastric refluxate, can evolve into a highly differentiated intestinal metaplasia, which resembles small-bowel mucosa. This proves that complete-type intestinal metaplasia may arise not only in the stomach, but also in the esophagus. Esophageal intestinalization seems to reflect adaptation to enteric reflux.

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.

Ki67 expression in different epithelial types in columnar lined oesophagus indicates varying levels of expanded and aberrant proliferative patterns

AIMS

To evaluate proliferative patterns in metaplastic columnar epithelia of the oesophagus, classified as oxynto-cardiac (n = 43), cardiac (n = 45) intestinal without dysplasia (n = 41), dysplastic intestinal epithelium (n = 25), and adenocarcinoma (n = 15) by Ki67 immunohistochemistry.

METHODS AND RESULTS

Abnormal patterns of Ki67 immunoreactivity were classified into (i) expanded proliferation, characterized by increased levels of Ki67 expression in the deep and mid third of the foveolar pit; and (ii) aberrant proliferation, characterized by positive staining in the surface epithelium and superficial third of the foveolar pit. A significant step-wise increase in the frequency of expanded proliferation was seen in oxynto-cardiac, cardiac, intestinal and dysplastic intestinal epithelium indicative of increasing levels of damage. Aberrant proliferation was absent in oxynto-cardiac mucosa, present at a low and similar level in cardiac, intestinal and low-grade dysplastic epithelia and at a significantly increased frequency in high-grade dysplasia.

CONCLUSIONS

These findings suggest that oxynto-cardiac mucosa occurs in a low damage environment and intestinal metaplasia in a high damage environment along the length of the columnar lined oesophageal segment. Aberrant proliferative patterns with Ki67 staining are not useful in differentiating reactive epithelia from low-grade dysplasia, but may prove useful in the diagnosis of high-grade dysplasia.

The genesis of Barrett esophagus: has a histologic transition from gastroesophageal reflux disease-damaged epithelium to columnar metaplasia ever been seen in humans?

Has a histologic transition from gastroesophageal reflux disease-damaged epithelium to columnar metaplasia ever been seen in humans? The answer to this question seems to be that it has but that we either do not readily recognize it or it is not readily recognizable with regular light microscopy. There are at least 3 possible mechanisms for the genesis of Barrett esophagus. The first is ulceration at the gastroesophageal junction with subsequent repair by an epithelium that differentiates into Barrett epithelium. The second is metaplasia through multilayered epithelium. The third is creeping columnar metaplasia at the Z-line proximally followed by intestinalization. These 3 hypotheses may not be mutually exclusive, and all may be operative, depending on the local circumstances, amount of inflammation, erosion, ulcers, healing, acid and alkaline reflux, and use of proton pump inhibitors. Any of the epithelial types involved could be stable and not progress. They might even be reversible, which may also in part explain the mosaic of epithelial types that typify Barrett esophagus, and may be modified by any of the molecular mechanisms that turn protein transcription on and off (eg, promoter methylation, mutations). These mechanisms ultimately may also be involved in the genesis of neoplastic transformation.

Controversies of the cardiac mucosa and Barrett's oesophagus

Confusion regarding the diagnosis of Barrett's oesophagus exists because of a false dogma that cardiac mucosa is normally present in the gastro-oesophageal junctional region. Recent data indicate that the only normal epithelia in the oesophagus and proximal stomach are squamous epithelium and gastric oxyntic mucosa. When this fact is recognized, it becomes easy to develop precise histological definitions for the normal state (presence of only squamous and oxyntic mucosa), metaplastic oesophageal columnar epithelium (cardiac mucosa with and without intestinal metaplasia, and oxynto-cardiac mucosa), the gastro-oesophageal junction (the proximal limit of gastric oxyntic mucosa), the oesophagus (that part of the foregut lined by squamous and metaplastic columnar epithelium), reflux disease (the presence of metaplastic columnar epithelium), and Barrett's oesophagus (cardiac mucosa with intestinal metaplasia). It is also possible to assess accurately the severity of reflux which is directly proportional to the amount of metaplastic columnar epithelium, and the risk of adenocarcinoma which is related to the amount of dysplasia in intestinal metaplastic epithelium present within the columnar lined segment of the oesophagus. Histopathological precision cannot be matched by any other modality and can convert the confusion that exists regarding diagnosis of Barrett's oesophagus to complete lucidity in a manner that is simple, accurate, and reproducible.

Gland ducts and multilayered epithelium in mucosal biopsies from gastroesophageal-junction region are useful in characterizing esophageal location

SUMMARY. There is controversy as to whether oxynto-cardiac mucosa (OCM), cardiac mucosa (CM) and intestinal metaplasia (IM) found in the gastroesophageal-junction region line the anatomic stomach, esophagus or both. A total of 785 retroflex biopsies taken at the endoscopic gastroesophageal junction in 244 patients were evaluated for the presence of gland ducts and multilayered epithelium which are two recognized markers of esophageal mucosa. Oxyntic mucosa was found in 287 biopsies, OCM in 283, CM in 158, IM in 30 and squamous epithelium in 53 (some biopsies had more than one epithelial type). Esophageal gland ducts and multilayered epithelium were absent in all biopsies with oxyntic mucosa. Sixty-four (13.6%) of 471 biopsies with OCM, CM and IM contained esophageal gland ducts, and 68 of 471 (14.4%) contained multilayered epithelium. Ninety-eight of 471 (20.8%) biopsies contained either gland ducts or multilayered epithelium. This study shows that 20.8% of biopsies at the gastroesophageal junction with OCM, CM and IM can be definitively characterized as lining the anatomic esophagus by the finding of gland ducts and multilayered epithelium. The absence of these markers in oxyntic mucosa confirms this epithelium as gastric. The presence of gland ducts and multilayered epithelium can be used by pathologists to objectively ascribe an esophageal or gastric location to a biopsy from the gastroesophageal junction.

CD1a expression by Barrett's metaplasia of gastric type may help to predict its evolution towards cancer

As emerging in the recent literature, CD1a has been regarded as a molecule whose expression may reflect tumour evolution. The aim of the present work was to investigate the expression of CD1a in a series of Barrett's metaplasia (BM), gastric type (GTBM), with and without follow-up, in order to analyse whether its expression may help to diagnose this disease and to address the outcome. Indeed, GTBM may be confused sometimes with islets of ectopic gastric mucosa and its evolution towards dysplasia (Dy) or carcinoma (Ca) could not be foreseen. We showed a significant higher expression of CD1a in GTBM than in both Dy and Ca; nevertheless, the number of positive GTBM was significantly lower in the group of cases that at follow-up underwent Dy or Ca. Our data address that CD1a may be a novel biomarker for BM and that its expression may help to predict the prognosis of this pathology.

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.

Histological inflammatory changes after surgery at the epithelium of the distal esophagus in patients with Barrett's esophagus: a comparison of two surgical procedures

There are many reports concerning the surgical treatment of patients with Barrett's esophagus, but very few focus on histological changes of inflammatory cells in squamous and columnar epithelium before and late after classic antireflux or acid suppression-duodenal diversion surgery. We evaluate the impact of these procedures in the presence of intestinal metaplasia, dysplasia and Helicobacter pylori in the columnar epithelium. Two groups of patients were studied, 37 subjected to classic antireflux and 96 to acid suppression-duodenal diversion operations. They were subjected to endoscopic and histological studies before and at 1, 3 and more than 5 years after surgery. Manometric evaluations and 24 h pH monitoring were performed before and at 1 year after surgery. The presence of inflammatory cells at both the squamous and columnar epithelium was significantly higher at the late follow up in patients subjected to classic antireflux surgery compared with patients subjected to acid suppression-duodenal diversion operations (P < 0.02 and P < 0.001, respectively). Intestinal metaplasia, present in 100% of patients before surgery, had decreased significantly at 3 years after surgery in patients subjected to acid suppression-duodenal diversion operations compared with classic antireflux procedures, 75% versus 53%, respectively (P < 0.001). The presence of Helicobacter pylori did not vary before or after surgery in either group. In conclusion, acid suppression-duodenal diversion operations are followed by a decreased presence of inflammatory cells in both squamous and columnar epithelium compared with classic antireflux surgery in patients with Barrett's esophagus. Intestinal metaplasia and dysplasia and inflammation findings were also less common after acid suppression-duodenal diversion operation.

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.

Cardia-type metaplasia arising in the remnant esophagus after cardia resection

BACKGROUND

Specialized intestinalized metaplasia in the distal esophagus (Barrett's esophagus) is a recognized precursor of esophageal adenocarcinoma, but its pathogenesis is incompletely understood. The aim of this study was to investigate the mucosal effects of esophagogastrostomy, an artificial interface between esophageal squamous and gastric oxyntic epithelium.

METHODS

EGD was performed in 14 consecutive patients (median age 63 years, range 26-71 years) who had undergone esophagogastrostomy from 3 to 88 months earlier. Biopsy specimens were obtained in 13 patients from the anastomosis and, when present, columnar epithelium in the remnant esophagus.

RESULTS

In 10 patients, EGD demonstrated tongue-shaped segments of columnar epithelium extending from 0.3 to 7 cm into the remnant esophagus. Biopsy specimens revealed cardia-type mucosa in all patients, whether at the anastomosis or proximally in esophageal segments of columnar epithelium. Magnification endoscopy of cardia-type mucosa visualized a long-oval, tubular, or ridged surface pattern. In 3 cases, complete intestinal metaplasia was observed within the cardia-type mucosa.

CONCLUSIONS

The frequent transformation of squamous epithelium into cardia-type mucosa in the distal remnant esophagus after esophagogastrostomy supports the concept that cardia-type mucosa is a reflux-induced metaplasia that may give rise to the subsequent development of specialized intestinalized metaplasia.

TFF3 expression at the esophagogastric junction is increased in gastro-esophageal reflux disease (GERD)

At the gastric cardia, the molecular mechanisms of inflammation and metaplasia are incompletely understood. Thus, the aim of this study was to determine the expression of TFF1, TFF2 and TFF3 at this site and correlate these data with Helicobacter pylori infection or gastro-esophageal reflux disease (GERD). In 27 patients without intestinal metaplasia at the cardia, endoscopic biopsies were obtained for histology and RT-PCR. TFF1 and TFF2 were expressed in all cardia samples. TFF3 expression was significantly more frequent at the cardia (n = 15/24) than in the corpus (n = 2/26). TFF3 expression at the cardia was mainly observed in GERD patients, and there was a clear tendency towards higher interleukin-8 (IL-8) transcription levels; whereas TFF3 expression was not correlated with the H. pylori status or to tumor necrosis factor-alpha (TNF-alpha) expression. The expression of TFF3 at the cardia may represent an adaptation to GERD and precede the development of Barrett's esophagus.

Reflux esophagitis: sequelae and differential diagnosis in infants and children including eosinophilic esophagitis

Gastroesophageal reflux disease (GERD) is a common condition in infants and children and has many clinical mimics. Most pediatric pathology departments process many mucosal biopsies from the proximal gastrointestinal tract to evaluate the presence or absence of reflux esophagitis. Since this subject was last reviewed in the 1997 edition of Perspectives in Pediatric Pathology devoted to gastrointestinal diseases in children (Dahms BB. Reflux esophagitis and sequelae in infants and children. In: Dahms BB, Qualman SJ, eds. Gastrointestinal Disease. Perspectives in Pediatric Pathology, vol. 20. Basel: Karger, 1997;14-34), progress in the field has allowed recognition of additional presenting symptoms and treatments of GERD. Histologic criteria for diagnosing reflux esophagitis have not changed. However, the entity of eosinophilic esophagitis has emerged since 1997 and has been defined well enough to allow it to be distinguished from reflux esophagitis, with which it was probably previously confused. Refinements (though not simplification!) in the definition of Barrett esophagus are still in evolution. This review will summarize these newer concepts and briefly review the standards of diagnosis of reflux esophagitis.

Carditis at the interface between GERD and Helicobacter pylori infection

Inflammation of the gastric cardia ('carditis') is a histological diagnosis. It seems reasonable to transfer histological criteria of the updated Sydney classification from the distal stomach to the cardia as long as a special classification of inflammation of the esophagogastric junction is lacking. The two best characterized causes of carditis are Helicobacter pylori infection and gastroesophageal reflux disease (GERD). However, the causal contribution and interference of these two factors are highly controversial, as is the clinical relevance of carditis in terms of eliciting symptoms or conferring an increased cancer risk. Variability of studies on carditis is based on conflicting concepts of the normal anatomy of the esophagogastric junction. Cardia-type mucosa (CM) apparently exists at birth as a tiny circular area, and extends to a larger area in adulthood. This implies that cardia-type mucosa is largely metaplastic. Metaplastic CM may evolve in the lower esophagus as a consequence of GERD. It is a general phenomenon that H. pylori-induced gastritis also involves the gastric cardia, irrespective whether the cardia is lined by fundus-type mucosa or CM. The contribution of GERD to inflammation of CM in H. pylori-negative individuals is, however, highly controversial. Prevalence of carditis in GERD patients fluctuates between 10 and 97%. Hence, because of its high frequency and low specificity, carditis can currently not be considered as a clinical entity. The role of carditis for the increasing incidence of cancer of the esophagogastric junction requires careful studies that include accurate description of the area with adequate biopsy protocols.

Predictors of recurrent specialized intestinal metaplasia after complete laser ablation

OBJECTIVES

The aim of this study was to determine whether specialized intestinal metaplasia recurs after complete laser ablation and to evaluate the persistence of colon epithelial protein in esophageal mucosa after laser ablation as a predictor of recurrence.

METHODS

A total of 31 patients with specialized intestinal metaplasia (Barrett's esophagus) underwent laser photoablation. Investigators without knowledge of treatment status evaluated serial hematoxylin and eosin-stained slides, Alcian blue-stained slides, and immunohistochemistry for the detection of colon epithelial protein (mAb Das-1).

RESULTS

Endoscopic ablation of specialized intestinal epithelium was accomplished in 21 patients after 6.5 +/- 1.2 laser sessions. Complications included one perforation, one UGI bleed and one stricture. Of eight post-laser recurrences, seven were successfully re-ablated; one developed adenocarcinoma requiring esophageal resection. Cardia-type mucosa was present by biopsy at the time of complete ablation in all eight recurrent cases despite a normal endoscopic appearance. Colon epithelial protein was detected in all 31 patients before ablation, six of 21 completely ablated patients before they recurred and all eight recurrences. Only two of 15 patients, colon epithelial protein negative at the time of complete ablation, developed recurrent Barrett's esophagus. Thus, cardia-type mucosa and persistent colon epithelial protein staining after complete ablation of specialized intestinal epithelium were predictors of future recurrence (p < 0.001).

CONCLUSIONS

Specialized intestinal epithelium was ablated by neodymium:yttrium-aluminum-garnet laser but recurred in eight of 21 (38%) of patients. Colon epithelial protein was present in all primary (31 of 31) and all recurrent (eight of eight) Barrett's esophagus. Recurrent specialized intestinal metaplasia may be deep to squamous epithelium. Replacement of specialized intestinal mucosa by cardia-type mucosa and persistence of colonic epithelial protein are predictors of recurrent specialized intestinal mucosa before its endoscopic or histological detection. Laser ablation of Barrett's epithelium is an investigational intervention that should be restricted to research protocols.

Chromoendoscopy: from a research tool to clinical progress

Chromoendoscopy, the intravital staining of gastrointestinal epithelia, provides additional diagnostic information with respect to the epithelial morphology and pathophysiology. Based on experience gathered mainly in Japan, chromoendoscopy is now in more widespread use, in particular to identify preneoplastic and neoplastic lesions. The most promising techniques are the depiction of squamous epithelium neoplasia of the esophagus with Lugol's solution, staining of Barrett's mucosa by methylene blue, including the potential to identify neoplasia, and the demarcation of neoplasia with indigo carmine in stomach and colon for local endoscopic resection. However, the optimal methodology is still to be defined as well as diverging results of diagnostic accuracy to be clarified. High-resolution and magnifying endoscopy have breathed new life into chromoendoscopy. Innovative applications and refinement of the existing ones are soon to be expected.

Barrett's esophagus can and does regress after antireflux surgery: a study of prevalence and predictive features

BACKGROUND

To investigate the factors leading to histologic regression of metaplastic and dysplastic Barrett's esophagus (BE).

STUDY DESIGN

The study sample consisted of 91 consecutive patients with symptomatic Barrett's esophagus. Pre- and posttreatment endoscopic biopsies from 77 Barrett's patients treated surgically and 14 treated with proton pump inhibitors (PPI) were reviewed. An expert pathologist confirmed the presence of intestinal metaplasia (IM) with or without dysplasia. Posttreatment histology was classified as having regressed if two consecutive biopsies taken more than 6 months apart plus all subsequent biopsies showed loss of IM or loss of dysplasia. Clinical factors associated with regression were studied by multivariate analysis, as was the time course of its occurrence.

RESULTS

Histopathologic regression occurred in 28 of 77 patients (36.4%) after antireflux surgery and in 1 of 14 patients (7.1%) treated with PPIs alone (p < 0.03). After surgery, regression from low-grade dysplastic to nondysplastic BE occurred in 17 of 25 patients (68%) and from IM to no IM in 11 of 52 (21.2%). Both types of regression were significantly more common in short (< 3 cm) than long (> 3 cm) segment Barrett's esophagus; 19 of 33 (58%) and 9 of 44 (20%) patients, respectively (p = 0.0016). Eight patients progressed, five from IM alone to low-grade dysplasia and three from low- to high-grade dysplasia. All those who progressed had long segment BE. On multivariate analysis, presence of short segment Barrett's and type of treatment were significantly associated with regression; age, gender, surgical procedure, and preoperative lower esophageal sphincter and pH characteristics were not. The median time of biopsy-proved regression was 18.5 months after surgery, with 95% occurring within 5 years.

CONCLUSIONS

This study refutes the widely held assumption that once established, Barrett's esophagus does not change. More than one-third of patients with visible segments of Barrett's esophagus undergo histologic regression after antireflux surgery. Regression is dependent on the length of the columnar-lined esophagus and time of followup after antireflux surgery.

Recurrent columnar-lined esophageal segments--study of the phenotypic characteristics using intestinal markers

Barrett's metaplasia is recognized by specialized columnar epithelium on the distal esophagus. The events involved in the transformation from squamous to Barrett's epithelium remain unclear. The present study describes the characteristics observed during the recurrence of four cases of columnar-lined esophagus. Red velvet, gastric-like, esophageal mucosa was observed to develop above the anastomosis during follow-up of four patients submitted to surgery for esophageal and junctional adenocarcinoma. The areas of recurrence were associated with reflux symptoms and inflammation, with ulceration in two cases. Biopsies from the upper gastrointestinal endoscopies were examined histologically using periodic acid-Schiff/Alcian blue to detect acid mucins and a monoclonal antibody raised against the enterocytic enzyme sucrase-isomaltase. In all cases the recurrent columnar-lined segments displayed intestinal features recognized morphologically, histochemically, and/or immunohistochemically. There was no evidence of specialized columnar epithelium in three cases. The fourth patient developed specialized columnar epithelium during the tenth year of surveillance. The presence of AB-positive columnar cells was a frequent and early event. Columnar cells with unequivocal apical sucrase-isomaltase were observed only in association with specialized columnar epithelium. Four conclusions were reached: that the development of columnar-lined mucosa without specialized columnar epithelium may be the earliest event in Barrett's metaplasia; that histochemistry is a useful method of recognizing a population with cryptic intestinal features; that acid mucin secretion precedes the production of enterocytic enzymes by columnar cells; and that a cell population with enterocytic differentiation, as assessed by sucrase-isomaltase expression, is associated with the development of specialized columnar epithelium. These characteristics of Barrett's esophagus development are clinically relevant as they suggest that patients with columnar-lined esophagus without specialized columnar epithelium may acquire 'true' intestinal phenotype, justifying them being considered as high- risk patients.

Histology of Barrett's esophagus and dysplasia

This article explores issues related to the diagnosis of Barrett's esophagus (BE) in endoscopic biopsies and dysplasia in Barrett's epithelium. The definitions of BE, including long- and short-segment BE, are reviewed, with an emphasis on the significance of intestinal metaplasia (IM). IM of the gastroesophageal junction and cardia is reviewed and problems in its distinction from short-segment BE are discussed. In addition, the article reviews the classification of dysplasia in Barrett's mucosa, with reference to problematic areas, such as sampling error and interobserver variability. Biomarkers and their role in the diagnosis of dysplasia and stratification of risk are summarized.

The gastric cardia: to be or not to be?

The origin and biologic significance of cardiac gastric mucosa are controversial. Traditionally, it has been considered native mucosa and part of normal foregut development. It has been recently suggested that cardiac mucosa is present only as a metaplastic response to gastroesophageal reflux disease and therefore always abnormal. We evaluated the esophagogastric junction in 100 pediatric autopsy samples to determine the existence, characteristics, and length of pure cardiac mucosa at different ages. No patient had a history of gastroesophageal reflux disease. Cardiac mucosa immediately distal and contiguous to the esophageal squamous mucosa was identified in all 100 samples, varying in length from 0.1 to 3 mm; the mean length was 1 mm. There was an inverse correlation between patient age and length of cardiac mucosa; gender had no influence on measured length. Three patients had mild to moderate histologic esophagitis; two had gastritis. No metaplastic features or Helicobacter pylori were identified. These findings support the concept that there is a normal, variably narrow developmental zone at the esophagogastric junction covered by cardiac mucosa and is present at birth. When cardiac type mucosa is found in biopsy material, it does not necessarily represent evidence of a mucosal metaplastic response to gastroesophageal reflux disease.

Cytokeratin and DAS-1 immunostaining reveal similarities among cardiac mucosa, CIM, and Barrett's esophagus

OBJECTIVE

The normal histology at the gastroesophageal junction, and in particular the nature of cardiac mucosa, remains in dispute. Likewise, the relationship of intestinal metaplasia at the gastroesophageal junction (CIM) to Barrett's and intestinal metaplasia of the stomach (GIM) is unclear. The aim of this study was to assess the immunostaining characteristics of cardiac mucosa and CIM and compare their staining pattern with that of other foregut mucosal types. We hypothesized that the immunostaining patterns of these foregut tissues would provide insight into the nature and etiology of cardiac mucosa and CIM.

METHODS

Paraffin-embedded biopsy specimens from 50 patients with normal antral or fundic mucosa, cardiac mucosa, squamous mucosa, CIM, GIM, or Barrett's were obtained and immunostained with a panel of monoclonal antibodies including those for cytokeratins 7 and 20 (CK7/CK20) and DAS-1.

RESULTS

Biopsies from normal gastric antral and fundic mucosa and squamous esophageal mucosa all showed a non-Barrett's type CK7/CK20 immunostaining pattern, whereas in 85% of patients, cardiac mucosa had a Barrett's type CK7/CK20 pattern (p < 0.001). A Barrett's type CK7/ CK20 staining pattern was seen in 100% of Barrett's, 78% of CIM, and 0% of GIM patients. Likewise, DAS-1 staining was similar in patients with CIM and Barrett's and significantly different in patients with GIM.

CONCLUSIONS

Cytokeratin immunostaining of cardiac mucosa demonstrates significant differences from recognized normal gastric and esophageal mucosa but a similarity to Barrett's. This suggests that cardiac mucosa, like Barrett's, may be acquired. Likewise, immunostaining similarities between CIM and Barrett's biopsies point to the possibility of a reflux etiology for CIM in some patients.