New aspects in the pathology of the preneoplastic lesions of the larynx.

In our 5-year biopsy study (1991 95) 51% of keratoses and 16% of adult-onset papillomas contained certain degrees of dysplasia. Koilocytosis associated with HPV infection was prominent in papillomas and the majority of keratosis but negligible in cancer. Using mouse monoclonal antibody against human p53 we detected by immunohistochemistry mutated p53 overexpression not only in cancer but in some cases of keratoses and papillomas. CD44 is a multifunctional integral cell membrane glycoprotein and is found in many mesenchymal, epithelial and tumor cells. CD44 has a great number of splice variants, isoforms supposedly implicated in development, progression and metastasis formation of tumors. Using monoclonal antibody to CD44 our study suggests that the expression of pan CD44 at successive stages of human laryngeal carcinogenesis gives preliminary information about the selection advantage to the tumor cells.