Thirteen patients who had adenocarcinoma of the prostate with micrometastasis to pelvic lymph nodes were treated with radical retropubic prostatectomy and pelvic lymphadenectomy, but no adjuvant hormonal therapy, and were followed until the documented appearance of metastasis to bone or soft tissue. Sections from the initial lesion, stained with hematoxylin and eosin and examined under the light microscope, revealed that the nucleoli in the primary Gleason pattern were "prominent" or "intermediate" (regardless of the Gleason grade) in nine cases; and the mean interval to progression was shorter in this group than in the group of four in whom nucleoli were judged to be "not prominent" (P = 0.015). Since the number of cases is small, the findings should be considered preliminary and their interpretation speculative; but the study is continuing.