Lance Armstrong.
Hold on, is he more evil?
The good news: cancer free - Yay!!!
The bad news: your weight loss program will not likely make you rich.
On the whole, net positive.
Congrats on the good news, Asmovian!
Great news from a fellow Asimovian!
Hmmmm…I still wish you the best, but just in case, would that be a right “eye” patch, or a left one? 
Great news! Glad you’re OK (and out of the woods).
congrats …. although one q if they would of figured it out before said jewel was removed would ya had to have it removed in the first place ?
Congrats!!
If you’re gonna be the one-in-a-gazillion oddity, you definitely want it to be in this direction vs the other!!
Unfortunately, there isn’t any good way to tell without the actual removal. Apparently, testicular biopsies are not usually considered a worthwhile risk because the biopsy can actually cause cancer to spread. There are some cases where they can open the scrotum and do kind of a real-time analysis of the tumor, but my limited understanding is that the type of pathology they can do during the surgery isn’t incredibly reliable.
Since a very, very large number of intratesticular tumors wind up being malignant (I believe the number I saw was greater than 95%), and since removal of the testicle and spermatic cord winds up being a cure for many cases of testicular cancer, especially when caught early, the radical orchiectomy is almost always recommended.
In testicular cancer, much like nuking things from orbit, it’s the only way to be sure.
Surgery is never fun, but I’m glad to hear that you had such a positive outcome, Asimovian. Best of luck in a fast recovery.