Formalin- or alcohol-fixed, paraffin-embedded laryngeal specimens were stained immunohistochemically with several kinds of monoclonal anti-Keratin antibody (KL-1, PKK-1, PKK-2, PKK-3), polyclonal anti-Keratin antibody, and epithelial membrane antigen.
Immunohistochemical technique was used by Avidin-Biotin Complex method with the following subjects ; normal epithelium 6 cases, dysplasia 15 cases, inflamation and polyp 12 cases, squamous cell carcinoma 47 cases. 6 specimens of squamous cell carcinoma were totally resected and alcohol-fixed, and other specimens were all biopsied and formalin-fixed.
Comparing these two methods, the alcohol-fixed specimen gave superior result to those obtained with formalin-fixed in its staining.
Non-staining area was recognized around basal layer by KL-1 stain in the normal epithelium. Enlargement of non-staining area was recognized in the dysplasia. Also, KL-1 staining showed positive staining with the keratinizing squamous cell carcinoma, and weak staining with the non-keratinizing squamous cell carcinoma. And, PKK-3 showed weak staining in the keratinizing squamous cell carcinoma. The results indicate that high molecular weight keratin (56 kilodalton) hardly localize around the basal layer in the squamous epithelium, and also in the non-keratinizing squamous cell carcinoma. The other way, this also suggests that low molecular weight keratin (45 kilodalton) hardly localize in the keratinizing squamous cell carcinoma. It is supposed that intracellular localization of keratin of dysplastic epithelium and squamous cell carcinoma varies from that in the normal squamous epithelium. Accordingly, monoclonal keratin stain is thought to be an useful method for the diagnosis of dysplasia and squamous cell carcinoma.