Primary Motility  Disorders of the  Esophagus
 The Esophageal
 Mucosa
 The
 Esophagogastric  Junction
 Barrett's
 Esophagus

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OESO©2015
 
Volume: Barrett's Esophagus
Chapter: Dysplasia
 

Are there specific cytometric features, such as cell and/or nuclear size and shape, that correlate with different grades of dysplasia?

J.W. van Sandick, J.P.A. Baak, W. Polkowski, G.J.A. Offerhaus, H. Obertop, J.J.B. van Lanschot (Amsterdam)

The diagnosis of dysplasia in Barrett's mucosa is based on architectural and cytologic abnormalities that suggest neoplastic transformation of the columnar epithelium [1, 2]. Increasingly severe dysplastic changes generally precede the development of invasive cancer [3, 4]. It has been emphasized that when regression of dysplasia to lower grades is observed at follow-up endoscopy, consideration should be given to an erroneous observation, due to either sampling error or diagnostic inconsistency in histological grading. Conventional grading of dysplasia in Barrett's mucosa is charged with substantial observer variation [5, 6]. Various techniques of quantitative pathology have emerged and potentially improve diagnostic accuracy in pathological grading [7]. For such techniques to have clinical utility in Barrett's esophagus, the method should objectively describe its stepwise histological progression, test results should be reliable, i.e., reproducible, and, measurements should be feasible on biopsy samples. One strategy is provided by quantitative analysis of cytometric and morphometric features using an interactive video overlay system [8, 9]. With a live, full-colour display of the microscopic image, the system has the advantage of preserving the tissue architecture. It enables measurements to be limited to the epithelial cells of interest, thereby excluding "contaminating" tissue components, such as stroma and inflammatory cells. Studies have revealed that the interactive quantitative method yields reproducible information on nuclear parameters (e.g. size, shape, stratification) in tissue samples from esophagectomy specimens [8], and in archival surveillance biopsies with Barrett's mucosa [9]. With respect to the "gold standard" (i.e., agreement on subjective grading by two expert pathologists), the most powerful discriminating feature between different grades of dysplasia was the stratification index (i.e., the relative position of each nucleus in the epithelium). Stereologic estimation of the mean nuclear volume could also objectively classify different grades of dysplasia. The mean nuclear area had discriminating power primarily between low-grade and highgrade dysplasia. Other morphometric variables associated with nuclear shape or variation in nuclear size (e.g. diameter, axis ratio) appeared of little or no help in distinguishing different grades of dyplasia. The stratification index had additional value in contributing to the unique classification of disagreement areas on subjective grading. This underlines the potential role of such quantitative assessment in resolving diagnostic dilemmas on subjective biopsy examination [10]. For its ultimate clinical application, discriminant thresholds await to be validated in a prospective setting.

It is of note that the quantitative parameters of nuclear size and nuclear stratification relate to indicators of neoplastic progression used in convential grading. In dysplastic Barrett's esophagus, as in other premalignant lesions of the gastrointestinal tract, increased proliferative activity is accompanied by an upward shift of DNA-synthesizing cells from the progenitor zone towards the luminal surface [11-13]. As a result, there is loss of differentiation and maturation with nuclear enlargement, an increased nuclear-cytoplasmic ratio, and pseudostratification. Objective diagnostic information on these morphologic changes that are indicative of dysplasia is obtained by quantitative assessment of nuclear size and nuclear stratification. Alternatively, subjective microscopic examination allows for reviewing additional tissue and cell abnormalities that are suggestive of neoplastic progression in Barrett's esophagus but difficult to assess with the quantitative methodology (e.g. villiform configuration of the mucosal surface, crowded and irregularly shaped glands, presence of dystrophic goblet cells with loss of polarity). It possibly explains some of the discrepancies between the gold standard and the quantitative classification results [8, 9]. In addition, sources of variation in quantitative pathology (e.g. object selection, measurement protocol) should be recognized, and repeated quality control has been emphasized [7]. An important requirement in quantitative assessment of Barrett's mucosa is area selection by an experienced pathologist. In return, computerized quantitation of nuclear size and nuclear stratification constitutes a simple, reproducible method with evolving properties to refine histological criteria for grading of dysplasia in Barrett's esophagus.

References

1. Hamilton SR. Adenocarcinoma in Barrett's oesophagus. In: Whitehead R, ed. Gastrointestinal and oesophageal pathology. Edinburgh:Churchill Livingstone, 1989:683-700.

2. Riddell RH, Goldman H, Ransohoff DF, Appelman HD, Fenoglio CM, Haggitt RC, Ahren C, Correa P, Hamilton SR, Morson BC, Sommers SC, Yardley JH. Dysplasia in inflammatory bowel disease:standardized classification with provisional clinical applications. Hum Pathol 1983;14:931-968.

3. Reid BJ, Blount PL, Rubin CE, Levine DS, Haggitt RC, Rabinovitch PS. Flow-cytometric and histological progression to malignancy in Barrett's esophagus: prospective endoscopic surveillance of a cohort. Gastroenterology 1992;102:1212-1219.

4. Van Sandick JW, van Lanschot JJB, Kuiken BW, Tytgat GNJ, Offerhaus GJA, Obertop H. Impact of endoscopic biopsy surveillance of Barrett's oesophagus on pathological stage and clinical outcome of Barrett's carcinoma. Gut 1998;43:216-222.

5. Reid BJ, Haggitt RC, Rubin CE, Roth G, Surawicz CM, Van Belle G, Lewin K, Weinstein WM, Antonioli DA, Goldman H, MacDonald W, Owen D. Observer variation in the diagnosis of dysplasia in Barrett's oesophagus. Human Pathol 1988;19:166-178.

6. Sagan C, Fléjou JF, Diebold MD, Potet F, Le Bodic MF. Reproducibilité des critères histologiques de dysplasie sur muqueuse de Barrett. Gastroenterol Clin Biol 1994;18:D31-34.

7. Baak JPA. The principles and advances of quantitative pathology. Anal Quant Cytol Histol 1987;9:89-95.

8. Polkowski W, Baak JPA, van Lanschot JJB, Meijer GA, Schuurmans L, ten Kate FJW, Obertop H, Offerhaus GJA. Clinical decision making in Barrett's oesophagus can be supported by computerized immunoquantitation and morphometry of features associated with proliferation and differentiation. J Pathol 1998;184:161-168.

9. Van Sandick JW, Baak JPA, van Lanschot JJB, Polkowski W, ten Kate FJW, Obertop H, Offerhaus GJA. Computerized quantitative pathology for the grading of dysplasia in surveillance biopsies of Barrett's oesophagus. J Pathol 2000;190:177-183.

10. Polkowski W, van Lanschot JJB, Offerhaus GJA. Barrett esophagus and cancer:pathogenesis, carcinogenesis, and diagnostic dilemmas. Histol Histopathol 1999;14:927-944.

11. Wesdorp ICE, Bartelsman JFWM, Schipper MEI, Offerhaus GJA, Tytgat GNJ. Malignancy and premalignancy in Barrett's oesophagus:a clinical, endoscopical and histological study. Acta Endosc 1981;11:317-326.

12. Offerhaus GJA, van de Stadt Samson G, Tytgat GNJ. Cell proliferation kinetics in the gastric remnant. Eur J Cancer Clin Oncol 1985;21:73-79.

13. Meijer GA, Baak JPA. Quantification of proliferative activity in colorectal adenomas by mitotic counts: relationship to degree of dysplasia and histological type. J Clin Pathol 1995;48:620-625.


Publication date: August 2003 OESO©2015