Cytokeratin 7 and 20 expression in intestinal metaplasia of the distal oesophagus: relationship to gastro-oesophageal reflux disease

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

CONTEXT.—

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

OBJECTIVE.—

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

DATA SOURCES.—

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

CONCLUSIONS.—

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

Gastro-esophageal reflux disease and Barrett's esophagus: an overview with an histologic diagnostic approach

The first part of this overview on non-neoplastic esophagus is focused on gastro-esophageal reflux disease (GERD) and Barrett’s esophagus. In the last 20 years much has changed in histological approach to biopsies of patients with gastro-esophageal reflux disease. In particular, elementary histologic lesions have been well defined and modality of evaluation and grade are detailed, their sensitivity and specificity has been evaluated and their use has been validated by several authors. Also if there is not a clinical indication to perform biopsies in patient with GERD, the diagnosis of microscopic esophagitis, when biopsies are provided, can be performed by following simple rules for evaluation which allow pathologists to make the diagnosis with confidence. On the other hand, biopsies are required for the diagnosis of Barrett’s esophagus. This diagnosis is the synthesis of endoscopic picture (which has to be provided with the proper description on extent and with adequate biopsies number) and histologic pattern. The current guidelines and expert opinions for the correct management of these diagnosis are detailed.

Single cell RNA-seq reveals profound transcriptional similarity between Barrett's oesophagus and oesophageal submucosal glands

Barrett's oesophagus is a precursor of oesophageal adenocarcinoma. In this common condition, squamous epithelium in the oesophagus is replaced by columnar epithelium in response to acid reflux. Barrett's oesophagus is highly heterogeneous and its relationships to normal tissues are unclear. Here we investigate the cellular complexity of Barrett's oesophagus and the upper gastrointestinal tract using RNA-sequencing of single cells from multiple biopsies from six patients with Barrett's oesophagus and two patients without oesophageal pathology. We find that cell populations in Barrett's oesophagus, marked by LEFTY1 and OLFM4, exhibit a profound transcriptional overlap with oesophageal submucosal gland cells, but not with gastric or duodenal cells. Additionally, SPINK4 and ITLN1 mark cells that precede morphologically identifiable goblet cells in colon and Barrett's oesophagus, potentially aiding the identification of metaplasia. Our findings reveal striking transcriptional relationships between normal tissue populations and cells in a premalignant condition, with implications for clinical practice.

Columnar Metaplasia in the Esophageal Remnant After Esophagectomy: A Common Occurrence and a Valuable Insight Into the Development of Barrett Esophagus

OBJECTIVE

This study aimed to establish the incidence of postesophagectomy columnar metaplasia and dysplasia, and the timescale over which it develops. It also aimed to assess if this epithelium is molecularly similar to sporadic Barrett esophagus, thereby confirming suitability as a research model.

BACKGROUND

Metaplasia in the esophageal remnant after esophagectomy is well described, but incidence and the potential for dysplasia are uncertain, and the clinical relevance unclear. Although proposed as a model for Barrett esophagus, no large studies have examined the molecular phenotype of postesophagectomy metaplasia.

METHODS

Patients underwent prospective endoscopic evaluation having previously undergone esophagectomy. The macroscopic appearance of the esophageal remnant was noted and biopsies taken. Specimens were stained using hematoxylin and eosin and by immunohistochemistry for cytokeratins 7 and 20, and Chromogranin A-proteins which have a well described expression pattern in sporadic Barrett esophagus.

RESULTS

Of the 126 eligible patients, 45 (36%) had evidence of metaplasia. There were no cases of dysplasia. Nonintestinalized columnar epithelium occurred earlier than specialized intestinal metaplasia (median 4.8 vs 8.1 yr; P = 0.025). Thirty-seven samples underwent immunohistochemical analysis. A classic cytokeratin 7/20 staining pattern was present in 23 cases (62%), within the prevalence range reported for sporadic Barrett.

CONCLUSIONS

Columnar metaplasia is common following esophagectomy, but the absence of dysplasia in this large cohort is reassuring. Presence of specialized intestinal metaplasia is associated with increased time from surgery, suggesting this represents later disease. Immunohistochemistry staining is similar to sporadic Barrett, suggesting that this group of patients represent an accurate human model for the development of Barrett.

Immunohistochemical features of the gastrointestinal tract tumors

Gastrointestinal tract tumors include a wide variety of vastly different tumors and on a whole are one of the most common malignancies in western countries. These tumors often present at late stages as distant metastases which are then biopsied and may be difficult to differentiate without the aid of immunohistochemical stains. With the exception of pancreatic and biliary tumors where there are no distinct immunohistochemical patterns, most gastrointestinal tumors can be differentiated by their unique immunohistochemical profile. As the size of biopsies decrease, the role of immunohistochemical stains will become even more important in determining the origin and differentiation of gastrointestinal tract tumors.

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

CONTEXT

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Characterization of esophageal submucosal glands in pig tissue and cultures

The submucosal glands (SMGs) of the pig esophagus, like the human, secrete mucin and bicarbonate, which help in luminal acid clearance and epithelial protection. The aim of this study was to characterize histochemically the esophageal SMGs and a primary culture obtained from these glands. Tissues and cultures were stained with hematoxylin and eosin, periodic acid Schiff, Alcian blue, lectins, or cytokeratins. In the perfused esophagus, addition of carbachol increased mucin secretion by approximately 2-fold. The results indicate that [1] a method for culturing SMG cells was developed; [2] conventional staining indicates the presence of sulfated, acidic, and neutral mucopolysaccharides in glands and cultures; [3] lectin binding indicates the presence of N-acetyl glucosamine, N-acetyl neuraminic acid, N-acetyl galactosamine, and alpha-L: -fucose in mucous cells and cultures; [4] cytokeratin and lectin staining indicated similarities with Barrett epithelium (columnar metaplasia of the esophagus); and [5] cholinergic agonists enhance mucin secretion and this could play a significant role in esophageal protection.

MODIFIED CLASSIFICATION FOR ADENOCARCINOMA OF THE GASTRO-OESOPHAGEAL JUNCTION

BACKGROUND

Incidence of the gastro-oesophageal junction adenocarcinoma is increasing. Siewert's classification subdivides junctional adenocarcinomas anatomically. Cytokeratin (CK) 7 and 20 immunophenotypes differentiate Barrett's intestinal metaplasia (IM) from gastric IM. Comparing CK immunostaining with Siewert's classification may establish tumour origin and influence surgical choice.

METHODS

In this experimental study, 57 patients with gastro-oesophageal junction adenocarcinoma were subdivided endoscopically into 15 type 1, 26 type 2 and 16 type 3 adenocarcinomas. Representative biopsies were immunostained for CK7 and CK20.

RESULTS

Intestinal metaplasia was associated with type 1 adenocarcinoma in 12 of 15 patients, 80%; with type 2 in 13 of 26 patients, 50% and type 3 in 6 of 16 patients, 37.5%. All type 1 patients showed Barrett's CK7/CK20 phenotype within IM; type 2 a mixture: 69% (n=9) Barrett's CK7/CK20 and 31% (n=4) gastric CK7/CK20 whereas type 3 patients had a gastric CK7/CK20 pattern in 83% (n=5). Immunostaining within the adenocarcinoma was variable.

CONCLUSION

Siewert's type 1 adenocarcinomas express Barrett's CK7/CK20 pattern, type 3 a gastric CK7/CK20 pattern and type 2 tumours a mixture of Barrett's and gastric CK7/CK20 patterns within associated IM. CK immunostaining may refine Siewert's classification into oesophageal type 1 or gastric type 2 adenocarcinoma with IM.

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

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

Pathologic Risk Factors of Adenocarcinoma of the Gastric Cardia and Gastroesophageal Junction

Available evidence supports the existence of two major pathways of neoplastic development in the gastroesophageal region: the Barrett pathway, related to gastroesophageal reflux disease, and the gastric pathway, related to Helicobacter pylori infection. The existence of an independent junctional pathway is questionable, and gastroesophageal junction adenocarcinomas share features of esophageal and gastric adenocarcinomas. It has been impossible to accommodate all data that are provided by different levels and tools of observation in tumors that develop in the gastroesophageal region in a single, coherent classification. That is why the stratification of pathologic risk in such tumors, and their respective precursors, incorporates features from topography, histology, immunohistochemistry, and molecular pathology.