Comparison of nuclear area measurements carried out on normal and dysplastic oral smears

We previously showed that quantitative cytology can help to detect oral cancer, not only at initial presentation but also in patients with unstable mucosa in whom recurrence has been detected prior to detection of a clinically obvious cancer. This has been due principally to the presence of a reduction in cytoplasmic area for Papanicolaou-stained cells and abnormal DNA distributions in Feulgen-stained nuclei collected from histologically confirmed dysplastic lesions. Furthermore, Feulgen-stained nuclei in oral smears that display abnormal DNA profiles appear to be larger than those in clinically normal smears, although an increase in nuclear area (NA) in Papanicolaou-stained smears is not always apparent. The aims of this study were to compare the mean NA values recorded for cells in Feulgen-stained smears with the values recorded for cells in Papanicolaou-stained smears collected from a selection of normal and abnormal sites to determine which of these smears produced mean NA values that correlated most closely with their DNA distributions. Forty patients with histologically confirmed epithelial dysplasia or invasive carcinoma and 20 patients with clinically normal mucosa were included in the study. NA values were obtained using image analysis. The mean NA values obtained from the Feulgen-stained smears were significantly elevated when compared with mean NA values obtained from Papanicolaou- stained smears of dysplastic lesions and invasive carcinoma and for clinically normal smears collected from these patients. This elevation in mean nuclear size, for Feulgen-stained smears, correlated closely with DNA distribution.