Proliferative epithelial changes in ectopic gastric mucosa of Meckel's diverticula.

Twenty-one Meckel's diverticula containing an adequate amount of assessable heterotopic gastric mucosa were investigated for epithelial changes. Marked or moderate foveolar hyperplasia was present in 52% and 29% of the cases, respectively. Four cases displayed an excessive epithelial proliferation indefinite for dysplasia. It is pointed out that reflux type gastritis or gastropathy, which is the most common lesion in the ectopic gastric mucosa of Meckel's diverticulum, can be associated with the same confusing epithelial proliferation as reflux gastritis in the stomach, but these lesions are best regarded as representing atypia of repair. Distinguishing features from dysplasia are maturation towards the surface, lack of hyperchromatism and abscence of atypical mitoses. Negative p53 immunostaining and localization of the Ki-67 positivity to the expanded neck region could be additive clues that can help to classify lesions indefinite for dysplasia as negative for dysplasia. On the basis of the similarities of the ectopic and ortotopic gastric mucosa, it is suggested that these additive clues previously used in other parts of the digestive tract could also apply for the stomach.