The effect of distant malignancy upon quantitative cytologic assessment of normal oral mucosa.

In 1962 Nieburgs et al. reported specific changes within cells taken from normal buccal mucosa, in those with malignant disease distant from the oral cavity. Few have attempted to confirm these findings. Given the potential application of the observations of Nieburgs et al., a quantitative investigation seemed necessary. Two groups were studied: 40 patients with malignant disease outside the oral cavity and 40 healthy patients attending for routine dental treatment. Both groups were matched for age and sex, with anemia excluded. Quantitative cytologic assessment of nuclear (NA) and cytoplasmic area (CA) and DNA distribution (using DNA cytophotometric study) were calculated from cells in normal buccal mucosal smears. No significant difference in NA (P = 0.28) was found between the two groups. However, a significant reduction in CA (P = 0.005) was found within the distant malignancy group. DNA distribution was invariably diploid. Previous studies on the effect of distant malignancy and nutritional deficiency have concentrated on examination of the nucleus, with exclusion of the cytoplasm. Important changes, such as the one reported, may therefore have gone unrecorded, particularly since oral smears have rarely been quantitatively assessed. The cause of this decrease in CA in distant malignancy patients is discussed with regard to the patients' nutritional state. The buccal smear may yet prove of value in assessing nutritional deficiency consequent to internal malignancy.