Atypical hyperplasia in prostates of 20 to 40 year old men.

One hundred prostates from 20 to 40 year old men obtained at necropsy were completely sectioned and studied microscopically. Atypical hyperplasia was found in 10 (20%) of 20-29 year old men and in 12 (24%) of 30-40 year old men. The prostates with atypical hyperplasia had similar weights as those without, and the atypical hyperplasia was most common in the lateral lobes of the prostate and near the apex. The atypical hyperplasias were (i) usually mild in degree rather than moderate or severe; (ii) almost equally divided between circumscribed and "infiltrating" lesions; (iii) usually occurred as multiple foci within the same prostate rather than as a single focus of atypical hyperplasia; and (iv) were not associated with inflammation. The finding that atypical hyperplasia is common in men between the ages of 20 and 40 years may be helpful in increasing the understanding of the histopathology of the prostate.