Silver staining nucleolar organizer region in prostate cytology.

Amongst males, the prevalence of prostate cancer is third in frequency with a rising incidence. As the population grows older, the number of latent cancer of the prostate increases. Therefore, diagnostic tools for an early detection of this malignancy are necessary. Silver staining of nucleolus organizer regions (AgNOR) is a new technique in tumour analysis. It is especially valuable as an addition to classical prostate cytology. A report on 90 cases of transrectal prostate aspiration biopsies is presented. 81 of these had a histological evaluation (biopsy gun) at the same time. The air-dried slides were stained according to Ploton et al. [10]. The AgNORs were counted and measured by means of an interactive image analysis system. Patients without malignancy were reliably classified as negative both by routine cytology as well as by AgNOR analysis. The sensitivity in routine tumor diagnosis was ca. 87%. In contrast, the AgNOR index revealed a sensitivity of 96% and a specificity of 97%. Thus, AgNOR staining improves differential diagnosis in inconclusive cases. Our data suggests that the inexpensive AgNOR analysis improves differentiation between carcinomatous and benign prostatic cells. It is a useful tool, in addition to routine prostatic cytology.