Nucleolar morphometry in fine needle aspiration biopsies of the prostate.

OBJECTIVE: To find efficient morphometric nucleolar features for distinguishing different prostatic atypia groups in fine needle aspiration biopsies. STUDY DESIGN: A computerized interactive morphometry program was used to outline nucleoli of prostate cells. The samples were divided into three groups: group 1 (definitely benign n = 10] and atypical but benign n = 13]), group 2 (moderately atypical n = 11] or highly suspicious n = 13]) and group 3 (definitely malignant n = 17]). RESULTS: The analysis revealed a difference in the number of nucleoli between definitely benign samples and other atypia groups but not between the latter. Nucleolar size features were best in distinguishing between atypia groups. The sample-associated mean size features were more powerful than cell group-associated size features. CONCLUSION: The sample-associated mean area, defined from cells selected by an experienced cytologist, if larger than 2 micron 2, was strongly associated with definitely malignant samples. The same was true for the largest nucleolar area if larger than 5.0 micron 2. Morphometric nucleolar size features appeared efficient in distinguishing between definitely malignant and other samples.