Exfoliative cytology of normal oral mucosa : Assessing the basal cell keratin phenotype

To attempt to evaluate the likelihood that normal keratin (antibody LH8) expression might contribute to a false positive diagnosis when sampling a lesion affecting the oral mucosa. Smears were taken from four oral sites (buccal mucosa, hard palate, dorsal tongue, ventral tongue) in 28 patients using the Axibrush. These were processed using a standard avidin-biotin technique, and the number of brown "positive" cells was assessed. None of the smears contained cells that were LH8 positive. While the results of this study suggest that exfoliative cytology is poor at sampling the basal cells of intact oral epithelium, it does indicate that the identification of LH8-positive cells in a smear from a clinically suspicious lesion is unlikely to be due to harvesting of normal basal cells.