CYTOKERATIN PATTERN OF CLINICALLY INTACT AND PATHOLOGICALLY CHANGED ORAL-MUCOSA

The various cytokeratin polypeptides in oral epithelia are expressed i n dependence on site and formation of a stratum corneum. Certain cytok eratins occur permanently and others occasionally. In fibrous hyperpla sia and Lichen ruber planus, patterns of cytokeratins did not deviate significantly from normal. In some but not all cases of squamous cell carcinoma and leukoplakia studied, marked aberrations of pattern were characterized by (i) appearance of cytokeratin No. 19, (ii) somewhat m ore frequent occurrence of cytokeratins Nos. 8 and 18, (iii) proteolyt ic modifications of cytokeratins, and (iv) partial loss of a few site- specific cytokeratins. The aberrations may be taken as additional diag nostic criteria for differentiation between non-aggressive and potenti ally aggressive leukoplakic lesion, even if they are not correlated wi th the conventional histological grading of dysplasia.