Many important advances have been made in the publication of the second series fascicle on this topic in 1973. The publication of this work is especially timely given the explosion of interest in the pathology of the prostate gland, and the current large volume of difficult prostatic biopsy specimens. Although accounting for a much lesser number of specimens, the pathology of the seminal vesicles, male urethra, and penis provides diverse challenges in interpretation. Furthermore, carcinoma of the penis, which is relatively common in certain parts of the world, has been the subject of a number of important recent studies. Accurate pathologic interpretations of all the entities that may be encountered in these regions, and the sometimes challenging distinction between benign and malignant, have major therapeutic implications.This fascicle emphasizes the differential diagnosis of carcinoma of the organs considered, particularly the distinction of carcinoma from mimics of cancer, tumor grading, and pathologic information of prognostic significance. It begins with a consideration of the normal anatomy and histology of the prostate gland followed by discussion of prostatic hyperplasia and the precursors of prostatic adenocarcinoma. The ensuing three chapters discuss conventional carcinoma of the prostate gland, variants of prostatic cancer, and miscellaneous other prostatic tumors. The final chapter on the prostate reviews in detail the numerous benign proliferations that may potentially be misinterpreted as neoplastic. Individual chapters are devoted to the seminal vesicles, male urethra, and penis. The emphasis of this work remains routine light-microscopic interpretation, which is diagnostic in the great majority of cases. The role of immunochemistry is emphasized where appropriate, for example, in the evaluation of problematic prostate proliferations and in confirming the prostate cell type of certain benign and malignant lesions. This 512-page fascicle, written by five pathologists with extensive experience evaluating genitourinary pathology, includes 835 color and 83 halftone illustrations. Every effort has been made to include the most current references as well as important contributions from the older literature.