Summary

Gastric dysplasia is believed to be the penultimate stage of gastric carcinogenesis. Its clinical importance has been underscored since its close association with gastric cancer was established. However, diagnostic criteria and grading schemes have evolved differently in different parts of the world. This has resulted in disagreement regarding differentiating features of both preinvasive and early gastric cancer between Western and Japanese histopathologists thereby preventing their direct comparison. Therapeutic guidelines are also controversial. On this background we review the current concepts and contemporary issues related to gastric dysplasia and early invasive carcinoma, their definition, classification, grading, natural history, potential therapy, and outline some of the recent efforts to harmonise the differences in terminology between Japanese and Western pathologists in order to produce a single classification system that would potentially be applicable throughout the gastrointestinal tract.

In the field of gastrointestinal pathology the term dysplasia is used by histopathologists to describe premalignant lesions.1-3 In the stomach, like any other segment of the gut, it is defined as an unequivocal neoplastic non-invasive epithelial alteration.1 ,4 The observation of gastric dysplasia as a precursor lesion of gastric cancer was made over a century ago, but it is only with the accrued use of upper endoscopy that its clinical significance has been stressed.5 Thus, the relevance of standardising the diagnostic criteria for gastric dysplasia and early invasive carcinoma, and of refining our understanding of its natural history have become increasingly important. However, to date, several unresolved issues pertain to gastric dysplasia: (a) lack of a uniformly recognised classification; (b) significant interobserver variability in microscopic diagnosis; (c) absence of well defined dysplastic features associated with the diffuse type of gastric carcinoma; (d) a limited understanding of the clinical significance of a diagnosis of dysplasia; and (e) variations in the therapeutic approach.

We …