THE EVALUATION OF SALIVARY-GLAND TUMORS USING PROLIFERATING CELL NUCLEAR ANTIGEN

In order to assess its discriminating and prognostic value, we studied the immunoreactivity for proliferating cell nuclear antigen (PCNA) in tissue from 52 human salivary gland tumours using the murine monoclon al antibody PC10. The PCNA percentage count, namely, the average numbe r of positive nuclei counted per 100 randomly selected tumour cells wa s recorded for each tumour. Anaplastic carcinoma was used as a positiv e control and histologically 'normal' salivary gland and tonsil served as a negative control. A PCNA count of 30 per cent was postulated to predict malignancy within a given salivary gland tumour i.e. a PCNA co unt of 30 per cent or above would indicate malignant potential. This g ave a sensitivity of 96.9 per cent and a specificity of 95.2 per cent and a positive predictive value of determining malignancy of 96.8 per cent. We conclude that PCNA immunoreactivity is useful in discriminati ng between benign and malignant salivary gland tumours and that it may have prognostic value in this diverse group of neoplasms.