The penis can be injured in a variety of ways. Blows to the groin, such as those that occur in sports, can result in excruciating pain or injury. Cuts that result from catching the penis in a pants zipper also are common, but they usually heal quickly. Less common are job-related accidents that sever the penis, either par- tially or fully. Reattachment may be possible, but full penile sensation and func- tion are rarely fully recovered.
Several types of inﬂammation problems may involve the penis and the ure- thra. Balanitis occurs when the glans, or head, of the penis becomes red and sore. Usually the cause is unknown, but it is sometimes caused by urinary tract infec- tion or allergic reactions to clothing or detergents. In uncircumcised men, the irritation may result when the foreskin is narrow or difﬁcult to retract, and secre- tions become trapped beneath the foreskin.
A more severe form of chronic inﬂammation, called balanitis xerotica oblit- erans, produces a hardened, whitish area near the tip of the penis and over the opening of the urethra. The cause is often unknown but may be an infection or an allergy. Antibacterial creams may cure the inﬂammation, but often surgery is required to open the urethra.
Phimosis is shrinking or tightening of the foreskin. This is normal in a newborn or an infant, but the foreskin usually loosens up by puberty. In older men, the condition may result from prolonged irritation, and it may interfere with urina- tion or sexual activity. Phimosis may be associated with penile cancer. The usual treatment is circumcision (surgical removal of the foreskin).
Paraphimosis is constriction of the head of the penis by an extremely tight, retracted (pulled back) foreskin. This often occurs as a result of phimosis (see above). Swelling and pain occur if the foreskin cannot be returned to its normal position over the head of the penis. The constriction also can cause loss of blood ﬂow to the head of the penis, which is a medical emergency that is usually treated by circumcision.
In some men, the penis becomes curved during an erection. This condition is called Peyronie’s disease. The cause is unknown, but ﬁbrous or scar tissue forms inside the penis and causes it to bend at an angle during an erection. This painful condition makes sexual penetration difﬁcult or impossible. The disease often resolves itself over several months. Vitamin E is the ﬁrst-line treatment for this condition. Injections of corticosteroids into the affected area are sometimes helpful. Ultrasound therapy also has worked for some men. Surgery may cure the disease, but it can cause further scarring and make the condition worse or cause erectile dysfunction.
Another rare and not well-understood disease is priapism, a painful, persistent erection not brought on by sexual desire or stimulation. The underlying cause (possibly drugs, blood clots, a tumor in the pelvis or the spine, infection of the genitals, sickle-cell disease, or leukemia) results in blood vessel and nerve abnormalities that trap blood in the penis during an erection. Immediate relief comes from draining excess blood from the penis with a needle and a syringe and irrigating the spongy tissue of the penis with an antihistamine ﬂuid to wash out any clots or other blockage.
Penile cancer is the growth of cancerous cells on the skin and in the tissues of the penis. It is rare in the United States—about 1,000 cases are reported each year, accounting for fewer than 0.02 percent of all male cancers in the nation. How- ever, 25 percent of those who develop the disease die of it. Penile cancer is linked
to the human papillomavirus (HPV; see page 184), which also causes cervical cancer in women.
Penile cancer can occur anywhere on the penis, but the most common sites are the glans (the head of the penis) and the foreskin (the fold of skin covering the glans). These cancers are usually slow growing, so the penis can be saved in most cases when the cancer is diagnosed early.
Penile cancer is most common in older men and African Americans, and the incidence rises steadily after age 55. Poor hygiene may be a risk factor for penile cancer in men who are uncircumcised. The theory is that if the penis is not kept clean, smegma, which is a buildup of mucus and other secretions, can collect under the foreskin and cause irritation and inﬂammation of the glans. This chronic irritation may set the stage for the development of cancer. Almost all cases of penile cancer occur in men who were not circumcised at birth.
Symptoms of penile cancer include a red spot, crust, wartlike growth, or sore on the penis; discharge from the penis; pain; a lump in the groin; or bleeding during an erection or intercourse. If you have any of these symptoms, see your doctor.
For a deﬁnitive diagnosis of cancer, affected areas of the penis are biopsied (tiny bits of tissue are removed for examination under a microscope). If cancer is detected, more tests are ordered to see if the cancer has spread to other parts of the body. In one test, called lymph node dissection, a needle is used to draw cells out of a lymph node (a gland that is part of the immune system) in the groin area. The cells are then examined to see if the cancer has spread to the lymph nodes.
The most common treatment for penile cancer is surgery, using one of the fol- lowing methods. Surgery may be followed by other treatments such as radiation or chemotherapy.
• Wide local excision. The cancer and some normal tissue on either side of the abnormal area are surgically removed.
• Microsurgery. The cancerous area, but little normal tissue, is removed. To do this, the doctor removes the cells while looking through the microscope.
• Laser surgery. The cancerous area is destroyed using a narrow, concentrated beam of light.
• Penectomy. The penis is partially or totally amputated. Although this is the most drastic method, amputation is the most common and most effective treat- ment for penile cancer. Lymph nodes also may be removed during this proce- dure. In partial penectomy, in which part of the penis is removed, some men remain capable of erection, orgasm, and ejaculation. Total penectomy leaves men signiﬁcantly impaired sexually, but in some cases, stimulation of the remaining tissue can produce orgasms.
• Radiation therapy and chemotherapy. These treatments are used after surgery.
• Biological therapy. This relatively new treatment involves injections of the protein interferon to enhance the body’s natural defenses against cancer. It is still considered experimental.
Other growths on the penis, such as warts, sores, and blisters, are almost always caused by infection (see chapter 9).