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

OBJECTIVE: To attempt to evaluate the likelihood that normal keratin (antibody LH8) expression might con tribute to a false positive diagnosis when sampling a lesion affecting the oral mucosa. STUDY DESIGN: 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. RESULTS: None of the smears contained cells that were LH8 positive. CONCLUSION: 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.