CLONAL STRUCTURAL CHROMOSOME-ABERRATIONS IN NONNEOPLASTIC CELLS OF THE SKIN AND UPPER AERODIGESTIVE TRACT

Cytogenetic analyses of tumors of the skin and upper aerodigestive tract have repeatedly revealed small, pseudodiploid clones characterized by balanced structural rearrangements and a high frequency of cells with nonclonal structural aberrations. However, the lack of common cytogenetic denominators within the different histologic subtypes, the discrepancy between cytogenetic findings and data obtained from flow cytometric DNA content studies, and the occasional identification of tumors with massively rearranged karyotypes indicate that the chromosome rearrangements present in pseudodiploid cells have little to do with the tumorigenesis or progression. Further support for this conclusion, and indirect evidence that the pseudodiploid clones probably do not represent the tumor cell populations, derives from the present study in which clonal and nonclonal structural rearrangements were also found in short-term cultures from nonneoplastic skin and pharyngeal mucosa. It is possible that the aberrations are present in subepithelial fibroblasts that have accumulated DNA damage due to extensive exposure to potentially carcinogenic agents.