One possibility can be Peyronie's disease, which is fibrosis or the formation of hardened tissue that can lead to penile curvature.
Calcified plaque can be identified with an X-ray or ultrasound.
Various conservative measures can be attempted, such as calcium channel blockers, or steroids.
Serere cases can be addressed by surgery.
These options can be discussed with your urologist, or in conjunction with a second opinion.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
http://www.straightfromthedoc.com