Comparison of Ki-67 and cytokeratin 20 (CK20) staining in atypical and typical hyperplastic polyps
| Staining pattern | Typical on light microspopy (n=26) | Atypical on light microspopy (n=31) |
|---|---|---|
| Usual pattern (Ki-67 positivity confined to lower crypt, CK positivity confined to upper crypt) | 17 | 11 |
| Upper crypt zone Ki-67 positivity, usual pattern CK20 positivity | 1 | 2 |
| Usual pattern Ki-67 positivity with basal CK20 positivity | 7 | 14 |
| Upper crypt zone Ki-67 positivity and basal CK20 positivity | 1 | 4 |
| p=0.036 for CK20 differences (Fisher's exact test; p value for the same or stronger association); p=0.19 for Ki-67 differences (Fisher's exact test; p value for the same or stronger association). | ||