Synonyms[]
Antibodies[]
Technical Info[]
Staining Pattern[]
Expression in Normal Tissues[]
- Colon
- Umbrella cells in urothelium[1]
- Merkel cells
Expression in Neoplastic Entities[]
Benign[]
| Tumor name | % Positive Staining | Number of Cases |
Intermediate/Uncertain Malignant Potential[]
| Tumor name | % Positive Staining | Number of Cases |
Malignant[]
| Tumor name | % Positive Staining | Number of Cases |
| Colonic Adenocarcinoma | 100%[2] | 20/20[2] |
| Merkel Cell Carcinoma | 78%[2] | 7/9[2] |
Expression in Non-Neoplastic Entities[]
Pertinent Negatives[]
This antigen is typically NOT expressed by the following entities:
- Usually negative in lung adenocarcinoma
Practical Uses / Panels[]
- Often used with CK7 to determine the origin of a carcinoma:
- Typically CK7+/CK20+ carcinomas:
- Pancreatic origin
- Ovarian origin (mucinous)
- Bile duct origin (extrahepatic, including gallbladder)
- Typically CK7+/CK20- carcinomas:
- Breast origin
- Lung origin
- Bile duct origin (intrahepatic)
- Endocervical/Endometrial origin
- Thyroid origin
- Typically CK7-/CK20+ carcinomas:
- Colon origin
- Typically CK7-/CK20- carcinomas:
- Prostate origin
- Adrenal cortex origin
- Typically CK7+/CK20+ carcinomas:
- Can be used to differentiate urothelial carcinoma in situ (cells below the umbrella cells are CK20+) from non-neoplastic urothelium (only the superficial umbrella cells are CK20+ [seen in normal urothelium])[3]