Dysplasia of the gastric mucosa and its relation to the precancerous state.

In an Expert Committee of the WHO, dysplastic changes of the stomach were defined as those having the following three histological features: (i) cellular atypia, (ii) abnormal differentiation and (iii) disorganized mucosal architecture. The changes were classified into three grades--mild, moderate and severe. This paper describes and illustrates each grade of dysplasia and discusses in detail the histological differences between severe dysplasia and intramucosal carcinoma. From the viewpoint of development of gastric cancer, severe dysplasia can be considered as one of the precursors. The clinical implications of dysplastic changes found in biopsied specimens are discussed.