Urothelial (Transitional Cell) Carcinoma In Situ (including flat hyperplasia and dysplasia)
Supplemental Studies
Immunohistology
- CK20
- Stains only umbrella cells in normal and reactive urothelium
- May stain diffusely in dysplasia
- Stains diffusely in most cases of CIS
- p53
- Negative in normal and reactive urothelium
- May stain diffusely in dysplasia
- Stains diffusely in most cases of CIS
- CD44
- Only basal cells stain in normal and hyperplastic
- Diffuse or patchy staining in reactive and atypia of unknown significance
- Negative in dysplasia and CIS
- Utility of markers is limited by lack of characterization of borderline cases
- We do not use these markers routinely for diagnosis of CIS
