Fig. 4.

 Low-grade dysplasia within macroscopically normal mucosa in the right colon. a Colonoscopy showed an inactive IBD without epithelial irregularities. b pCLE showed irregular crypts and dark epithelium classified as a dysplasia suspicion (score 3 according to Kuiper). c Histopathology showed the presence of low-grade dysplasia in flat mucosa, magnification 20 ×. d Staining for p53 showed strong overexpression indicating mutated p53 in the dysplastic epithelium (40 ×). e Staining for P405S showed an overexpression (40 ×). f Staining for cytokeratin 7 showed a weak overexpression (40 ×). g Staining for cytokeratin 20 was positive in whole crypts (20 ×). h Staining for Mib-1 (Ki-67) showed an increased proliferative activity (40 ×). Immunohistochemistry panel shows the presence of low-grade dysplasia