Figure 3.

β-Catenin expression in small adenomas. β-catenin is highly expressed and distributed throughout the dysplastic epithelium at the top of the crypts, where it is found in the nucleus as well as in the cytoplasm and plasma membrane (A and B). In contrast, staining is less intense in the normal-appearing epithelium at the bottom of the crypts, and staining is confined to the membranes (A and B). The staining pattern at the bottom of the adenomatous crypts is similar to that observed in normal colonic epithelium unassociated with neoplasia (C).