Keratin is a major class of epithelial intermediate filaments and comprises a group of at least 20 different multigene derived proteins. It is expressed in different epithelia with specific combinations. The expression of cytokeratins (CK) 1.5/6, 7, 8...
Keratin is a major class of epithelial intermediate filaments and comprises a group of at least 20 different multigene derived proteins. It is expressed in different epithelia with specific combinations. The expression of cytokeratins (CK) 1.5/6, 7, 8, 10, 13, 17, 18, 19, and 20 in 35 cases of squamous cell carcinomas from uterine cervix (5 cases), lung (5 cases), esophagus (5 cases), skin (5 cases), oral cavity (5 cases), and metastatic Iymph nodes (2 cases of each organs) were examined. Some cases were examined by electron microscopy.
The results obtained is as follows.
1. The CK 1 positive tumors is from keratinizing skin tumor and is show weak positivity. The CK 5/6 positlve tumor is from uterine cervix, lung and oral cavity. The CK 8 positive tumor is from uterine cervix, lung, esophagus, skin and oral cavity. The CK 13 positive tumors is from uterine cervix and lung. The CK 17 show positive staining in uterine cervix and lung. The CK 18 positive tumors is from uterine cervix, lung, esophagus, skin, and oral cavity. The CK 19 positive tumors is from uterine cervix, lung, esophagus, skin, and oral cavity. The CK 20 shows no reactivity in all cases.
2. Ultrastructurally, the tumor cells showed bundles of tonofibriIs, electron-dense tonofilaments, and desmosomes.
In conclusion, CK 1,8 18 and 19 did not show orgn specificity. So it used simple epithelial markers in the majority of squamous cell carcinomas. The absence of CK 20 immunoreactivity may helpful in differential diagnosis of squamous cell tumors.