CK5 and its partner CK14 constitute up to 25% of total cell protein in basal cells of epidermis; expression in skin correlates with mitotic activity (Science 1998;279:514, J Biol Chem 1995;270:21362, Development 1994;120:2369)

Cytokeratin 5 (CK5) is a protein made by epithelial cells in the skin, breast, salivary glands, urinary tract, and upper aerodigestive tract. Within these organs, CK5 is commonly seen in specialized squamous cells, basal cells, and myoepithelial cells.

Cytokeratin 5/6 (CK5/CK6) antibodies are for example applied to identify basal cells or myoepithelial cells for ruling out invasive breast and prostate cancer, to detect squamous cell origin in poorly differentiated carcinomas , and to distinguish epithelioid mesothelioma (mostly CK5/6 positive) from lung adenocarcinoma (mostly CK5/6 negative) .

Keratin 5 (and K14) are expressed primarily in basal keratinocytes in the epidermis, specifically in the stratified epithelium lining the skin and digestive tract.

The differential diagnosis for small round blue cell tumors of the skin and subcutis includes primary cutaneous neoplasms (e.g. small cell variants of melanoma and adnexal carcinomas, as well as MCC), certain soft tissue neoplasms, metastatic carcinoma - particularly small cell lung carcinoma, and lymphoma.

The diagnostic utility of immunohistochemistry in distinguishing primary skin adnexal carcinomas from metastatic adenocarcinoma to skin: an immunohistochemical reappraisal using cytokeratin 15, nestin, p63, D2-40, and calretinin.

We study the utility of p63, CK 5/6, CK 7, and 20 expression in PCAN vs. MC. Methods: Twenty-one PCAN with sweat gland differentiation (six benign, 15 malignant), one sebaceous carcinoma, and 15 MC (14 adenocarcinomas, one urothelial carcinoma) to …

2021年9月24日 · CK5 was the predominant staining in mesothelioma, basal cell carcinoma of the skin, urothelial carcinoma, thymoma, and salivary gland tumors, while CK6 predominated in various adenocarcinomas. It was noticeable for all tumor entities that either CK5 or CK6 was the predominant staining and that adding the second cytokeratin did not relevantly ...

Lin et al discovered that CK5, CK8 and CK14 can be expressed in the sweat gland tissues, while only CK5 and CK14, instead of CK8, can be expressed in the sebaceous gland. El-Khoury et al ( 13 ) revealed that different types of CK expression levels are present in different hair structures.

In contrast to cutaneous adnexal tumors, metastatic adenocarcinomas to the skin are cytokeratin 5/6 (CK5/6) and p63 negative in the majority of cases. It is unclear if failure to stain with CK5/6 and p63 would be helpful in differentiating WDNETs from cutaneous adnexal neoplasms.