Cytokeratin 14

This is an acidic cytokeratin. It is expressed by myoepithelium and by the basal cells of keratinised squamous epithelium.

Immunohistochemical expression

Normal tissues:

myoepithelial cells of breast glands and ducts
myoepithelial cells of salivary gland ducts and acini
basal layer of epidermis and squamous mucosa

Carcinomas:

Organ

squamous carcinoma

adenocarcinoma

other

head and neck

27/30¹

oesophagus

14/14¹

lung

13/15¹, 35/37² , 18/34⁸

2/10¹, 7/33² , 0/29⁸

poorly differentiated

0/3⁸

small cell

1/7¹, 2/37²

carcinoid

0/9¹

pleura

mesothelioma

3/171 (When present, staining was focal and corresponded to areas of squamous differentiation.), 16/30 ( 12/23 epithelioid, 4/7 sarcomatoid: usually <5% of cells stained)⁶

breast

lobular carcinoma

0/6¹, 0/7⁸

ductal carcinoma

0/20¹, 4/54⁸

stomach

0/8¹

colon

1/20¹, 0/61⁸

liver

hepatocellular

0/11¹

cholangiocarcinoma

1/14¹

pancreas

1/13¹

parotid

pleomorphic adenoma

4/5¹

kidney

0/19¹

bladder

pure squamous cell carcinoma

4/4³

transitional cell carcinoma

5/24¹,9/19 ³

foci of squamous differentiation in transitional cell carcinoma

15/16³

prostate

0/18¹ , 0/64⁸

uterus

cervical

13/15¹

endometrial

1/10¹

ovary

3/24¹, 4/45 (0/7 clear cell, 0/4 endometrioid, 0/2 mucinous, 4/32 serous papillary)⁸

skin

Melanoma

0/25⁸

Merkel cell tumour

0/9¹

gastrointestinal tract

carcinoid

0/15¹

thymus

thymoma

8/8¹

adrenal

cortical carcinoma

0/10¹

thyroid

follicular carcinoma

0/5¹

follicular adenoma

1/24¹

papillary carcinoma

0/10¹

medullary carcinoma

0/16¹

brain

glioblastoma

0/22⁸

miscellaneous

epithelioid sarcoma

0/12¹

neuroendocrine carcinoma

0/9¹

germ cell tumour

0/14¹

Overall

92% (102/111)

7% (16/221)

The frequency of immunoreactivity of squamous cell carcinomas appears to be independent of the degree of differentiation. Considering the squamous cell carcinomas listed above:

Cytokeratin immunoreactive

well differentiated

8/9¹

moderately differentiated

33/35¹

poorly differentiated

26/30¹

There is preliminary evidence that oncocytic tumours are immunoreactive, including Hurtle cell adenomas of the thyroid, Warthin tumours of the salivary glands and oxyphil adenomas of the parathyroid⁴.

Diagnostic utility

Identification of squamous cell carcinomas, particularly those which are poorly differentiated. It may be used in combination with p63 and CK5/6⁸.
Differentiation of oxyphil adenomas from carcinomas of the parathyroid⁴.
Differentiation of intraduct from invasive salivary duct carcinoma by the positive staining of basal cells surrounding the in-situ neoplasm⁵.
Differentiation of benign from malignant prostatic glands. Staining is often very intermittent, and is absent from some benign glands, while background staining is stronger than for either LP34 or CK5/6. The latter are probably therefore superior for this usage⁷.

References

¹Chu, P. G., Lyda, M. H., Weiss, L. M. Cytokeratin 14 expression in epithelial neoplasms: a survey of 435 cases with emphasis on its value in differentiating squamous cell carcinomas from other epithelial tumours. Histopathology 2001;39:9-16.

²Lyda, M. H., Weiss, L. M.. Immunoreactivity for epithelial and neuroendocrine antibodies are useful in the differential diagnosis of lung carcinomas. Human Pathol 2000;31:890-897.

³Harnden, P., Southgate, J. Cytokeratin 14 as a marker of squamous differentiation in transitional cell carcinomas. J Clin Pathol 1997;50:1032-3.

⁴Erickson, L. A., Jin, L., Papotti, M., Lloyd, R. V. Oxyphil parathyroid carcinomas: a clinicopathologic and immunohistochemical study of 10 cases. Am J Surg Pathol 2002;26:344-349.

⁵de Araujo, V.C., Kowalski, L.P., Soares, F., de Araujo, N.S., Loducca, S.V. and Sobral, A.P. Salivary duct carcinoma: cytokeratin 14 as a marker of in-situ intraductal growth. Histopathology 2002;41:244-9.

⁶Miettinen, M., J. Limon, et al. (2001). "Calretinin and other mesothelioma markers in synovial sarcoma: analysis of antigenic similarities and differences with malignant mesothelioma." Am J Surg Pathol 25(5): 610-7.

⁷Freeman, A., K. Treurnicht, et al. (2002). "A comparison of basal cell markers used in the prostate." Histopathology 40(5): 492-4.

⁸Reis-Filho JS, Simpson PT, Martins A, Preto A, Gartner F,Schmitt FC Distribution of p63, cytokeratins 5/6 and cytokeratin 14 in 51 normal and 400 neoplastic human tissue samples using TARP-4 multi-tumor tissue microarray. Virchows Arch 2003; 443:122-32 This study used tissue microarrays.

This page last revised 15.3.2005.