Peyronie\s Disease
Peyronie’s disease occurs when fibrous scar tissue, or plaque, forms inside the penis, usually within the tunica albuginea, the elastic layer that surrounds the erectile tissue. During an erection, the healthy portions of the penis expand normally, while the scarred area does not stretch in the same way. This can pull the penis toward the affected side and produce an abnormal curvature.
Source: https://www.dotclinics.pk/peyronie-disease