The penis normally has a slight curvature, within 250 degrees of a straight line. Sometimes newborn boys may have a sharp bend, which is usually associated with hypospadias and other abnormalities.
However, when the penis is bent beyond this degree in an adult, it is known as Peyronie's disease. This abnormal curvature is most obvious during erection. It is due to the formation of a fibrous band inside the penis which restricts the normal enlargement that accompanies erection. It affects 1-8% of men, mostly in the age group of 40-70 years.
It is more common following surgical or radiation treatment for prostate cancer. Possibly this is due to scarring following surgical, radiation or accident-induced injury to the cells inside the penis. It is also more common in men with hypertension or diabetes.
The injury may possibly not be acute, but rather a series of repeated injuries due to vascular blockages, minor trauma during athletic movement or even intercourse. However, this mechanism has not been proven. In fact, most injuries of the penis associated with intercourse heal without future pain or difficulty during penetration. Men with the blood marker HLA-B7 are at higher risk for Peyronie's disease. The disease also has a familial tendency.
Another rare cause for penile curvature is Dupuytren's contracture, a condition in which fibrous tissue forms across the palms, producing an inward claw-like folding. This condition is seen usually in Caucasian men over the age of 50, but very few of them develop curvature of the penis.
This condition is characterized by:
- painful erections
- pain and difficulty during intercourse, which is often the earliest symptom
- swelling and pain in the penis after intercourse
- shortening and narrowing of the penis in some cases
- an easily felt firm area or lump inside the penis, at the point of curvature
- obvious indentation at the site of curvature, because of the presence of scar tissue
- inability to have intercourse due to the severe curvature of the penis
- painless but very obvious curvature with an easily palpable firm area
- depression and other mental symptoms due to interference with normal life
The disease may be mild or severe, and has two phases. The first acute phase is more painful, and lasts between 1-2 years. This is followed by a lessening of pain, but the plaque then becomes more calcified and is harder to treat. As the disease progresses, it produces a permanent angulation of the penis, erectile dysfunction, total failure of penetration and often depression.
Diagnosis and treatment
Diagnosis is made by palpating the fibrous plaque inside the penis. Sometimes an ultrasound of the penis, with dye injection into the spongy part, is helpful in localizing the fibrosed part, especially when treatment is being planned. An X-ray will show calcium deposits when present. Sometimes a photograph of the erect penis is required to determine the degree of fibrosis. If surgical repair is being planned, there may be a need for more detailed testing of the penis to map out the best way to repair it.
Treatment options were limited till of late, and were associated with a high risk of serious side-effects such as increased fibrosis and scarring, or impotence. It is important to realize that none of these are proven to be beneficial in all cases, and most are useful only in some men, in the acute phase.
Initial treatment includes;
- injections of corticosteroids into the fibrous tissue to reduce inflammation
- oral treatment with drugs like pentoxifylline, colchicine, vitamins such as vitamin E
- shockwave lithotripsy to break up the hard plaque
- other medications such as PABA, verapamil or tamoxifen
Colchicine inhibits actively growing cells and is supposed to prevent fibroblast proliferation and fibrous tissue deposition. Verapamil is usually used to treat hypertension, but is helpful in Peyronie's disease by breaking down a protein involved in scarring.
Recently an injectable form of the collagenase enzyme from the bacterium Clostridium histolyticum has been used successfully to treat this condition. This enzyme breaks up the fibrous collagen tissue of the scar. Alpha-interferon injections are also being used with some success.
Surgery is the last resort, and is indicated in case of intractable pain during intercourse, when the degree of curvature makes intercourse impossible, or when the disease has entered the chronic phase despite the use of other treatment methods. It carries the risk of impotence, and may entail the insertion of a penile prosthesis. Surgery should always be delayed till the disease has clearly stopped progressing, to prevent the formation of a fresh fibrous scar following the surgical procedure.