Hi all. I found this thread while researching something for my son. I can verify,for anyone questioning, that males can indeed have 3 functional testicles. My son, now 26, was diagnosed as possibly having testicular cancer at the age of 14 (in 1995). After MANY tests over several months, and many specialists including several conferring (confused) urologists and radiologists, it was determined that he not only had 3 testicles, but that what they thought had been a "mass" was actually a completely functional third testicle, resting in the same sac as his left testicle above the lower one.
Three urologists working to diagnose the issue were elated to have finally diagnosed it, and said that in all their years of combined experience (over 75 yrs), they had not only never seen a functional third testical, but had not been able to find any medical case histories at that time regarding the issue. They told me that the only scenario they could think of that would support a completely functional third testicle would be if he'd been a twin. They said that not knowing that he had been a twin, but his twin had not survived the pregnancy. I am also a twin. When I told them that, they said they were as positive as they could scientifically be that the third testical was "absorbed" by my surviving son from his brother before birth.
Bottom line they stated was that he would only need medical intervention if it grew too large and put pressure on the testicle below on the same side, or if he was having pain. So far, so good. The original urologist made the comment that if no pain or further growth was experienced, then the only side effect would be that he would be a "VERY manly kinda man", ha. Hope this helps anyone questioning completely functional third testicles. They do exist, although apparently rare.
Edited to add the comment that from outward appearances, no one would ever know he has a third testicle, since the side with two are enclosed together in the sac, one resting on top of the other.
