Orchiopexy: surgical placement of an undescended testis. The risk factor here is the scrotal surgery, not the procedure itself.
Age: most common in young adults 20-40 years
Race: whites are 6 times more likely to develop testicular cancer than blacks
Vasectomy: surgical separation of the seminal vesicles for contraception. The risk factor here is the scrotal surgery, not the vasectomy.
Testicular trauma: crushing injury, blunt trauma (such as getting kneed in the groin) and other accidental injuries; risk of cancer is not known but is under investigation.
Other: Orchitis (inflammation of the testicle); irradiation
Men with cryptorchidism or undescended testes—the failure of one or both testicles to descend from the pelvis (about 10 percent of men with testicular cancer have a history of cryptorchidism)