Prostate gland specimens account for a significant percentage of diagnostically challenging cases in surgical pathology practice. The understanding of prostate pathology has progressed, and the differential diagnosis of prostatic carcinoma has expanded to include possible premalignant lesions and several recently described pseudocarcinomatous lesions. The authors discuss the histopathology of prostatic intraepithelial neoplasia and atypical adenomatous hyperplasia, review the evidence for their role as premalignant lesions, and discuss the criteria that allow for their distinction from prostatic adenocarcinoma. Pseudocarcinomatous lesions that must be recognized when assessing prostatic tissue include sclerosing adenosis, cribriform hyperplasia, mesonephric hyperplasia, and basal cell hyperplasia. The pathologic features and diagnostic challenges of these and other pseudocarcinomatous lesions are reviewed.