Cytokeratin 5 (CK5, K5)

Author: Nat Pernick, M.D. (see Authors page)

Revised: 4 December 2015, last major update October 2013

Copyright: (c) 2003-2015,, Inc.

PubMed Search: ck5[title]
Cite this page: Cytokeratin 5 (CK5, K5). website. Accessed April 24th, 2018.
Definition / general
Uses by pathologists
Positive staining - normal
Microscopic (histologic) images

Images hosted on Pathout server:

Contributed by Leica Microsystems, Biosystems Division-

Mesothelioma-Cytokeratin 5 (XM26) with intense cytoplasmic and membranous staining

Images hosted on other servers:

Breast carcinoma-basal subtype in BRCA1 patient

Gallbladder adenosquamous carcinoma


Mesothelioma deciduoid

Squamous cell carcinoma-oral (fig a)

Benign epithelial inclusions of axillary lymph nodes - fig 1: CK5/6+; 2: p63+

Images hosted on

Breast - various

Ovarian serous carcinoma

Pancreas-adenosquamous carcinoma

Various images #1 (squamous cell-fig 1A, urothelial-fig 1C, thymoma-fig 1E, salivary gland adenoid cystic-fig 1G)

#2 (ovary-fig 2A, endometrioid adenocarcinoma of uterus-fig 2C, infiltrating ductal carcinoma of breast-fig 2E)

Additional references