Peyronie's disease, a condition of uncertain cause, is characterized by a plaque, or hard lump, that forms on the penis. The plaque develops on the upper or lower side of the penis in layers containing erectile tissue. It begins as a localized inflammation and can develop into a hardened scar.
Cases of Peyronie's disease range from mild to severe. Symptoms may develop slowly or appear overnight. In severe cases, the hardened plaque reduces flexibility, causing pain and forcing the penis to bend or arc during erection. In many cases, the pain decreases over time, but the bend in the penis may remain a problem, making sexual intercourse difficult.
Sources
National Kidney and Urologic Diseases Information Clearinghouse
