The relationship between several morphonuclear parameters related to nuclear densitometry (DNA content and ploidy), and the chromatin pattern of Feulgen-stained nuclei is confronted to the histopathological grading of 39 prostatic samples obtained from surgical adenomatous or transurethral resection. We use a SAMBA 200 cell image processor with software allowing for the setting up of preliminary data banks that enable carrying out an objective and reproducible grading of unknown cases obtained from core biopsies of fine-needle aspirations. The present approach must be validated prospectively on a large series of cases in order to create an expert system for diagnosing such fine-needle aspirations from prostate.