Cytokeratin 7 is a basic cytokeratin found on many glandular and transitional epithelia.
Cytokeratin 7 is usually present in adenocarcinomas of:
Breast2
Ovary; serous and endometrioid tumours
Uterine cervical tumours
Biliary epithelium and cholangiocarcinoma
Transitional cell carcinoma of the bladder
It is usually absent from:
Squamous cell carcinomas
Mucinous adenocarcinoma of the ovary
Hepatocytes and hepatocellular carcinoma
Prostate and prostatic adenocarcinoma
conventional carcinoma |
0/10 |
chromophobe carcinoma |
9/9 strong membrane staining (7 diffuse and 2 focal), |
oncocytoma |
8/8 focal weak to moderate cytoplasmic staining without membrane accentuation |
The coordinate expression of cytokeratins 7 and 20 is particularly useful in identifying the primary site of adenocarcinomas.
Renal carcinomas: differentiation of conventional carcinoma, chromophobe carcinoma and oncocytoma1.
Identification of ovarian granulosa cell tumours and differentiation from carcinomas (especially endometrioid carcinoma with a sex cord-like pattern)
References
1 ME Mathers et al. Investigation of cytokeratin 7 expression in chromophobe renal cell carcinoma. Abstract 181, Pathological Society of Great Britain and Ireland January 2001.
2 Jerome Marson, V., J. Mazieres, et al. (2004). "Expression of TTF-1 and cytokeratins in primary and secondary epithelial lung tumours: correlation with histological type and grade." Histopathology 45(2): 125-34.
©SMUHT/PW Bishop