The problem in treating incidental carcinoma of the prostate is that of distinguishing between tumors that will have a long, benign natural history and those that will progress rapidly. A review of the English literature concerning incidental prostatic carcinoma reveals that patients with focal low grade tumors have a good prognosis, while patients with high grade lesions often suffer rapid tumor progression. By contrast, the clinical significance of high volume, low grade tumor is unknown. A method has been developed to evaluate the distribution of prostatic cancer using 4-quadrant transurethral prostatic resection. A detailed method for staging these cancers based on a comprehensive, segmental histopathological analysis also is presented. A precise definition of the stages of prostatic cancer should eventually improve our understanding of the natural history of this disease.