In 2018, Ben Walborn, a then-37-year-old airline pilot and Navy reservist, was on vacation with his family in Florida when he made a startling discovery. During a shower, he noticed his right testicle was double the size of the left one.

He promptly went to the Navy hospital in Pensacola, where personnel performed an ultrasound.

"They're like, 'We want to remove it,'" Walborn said. "I'm like, 'No, I'm on vacation and I don't even live here.' They said, 'I suggest you cut your vacation short, go home and see the first urologist who will see you.'"

So that's what Walborn did.

The urologist looked at the ultrasound and said he needed to remove the right testicle that night. Walborn underwent an orchiectomy, the term for the outpatient surgery that removes the testicle.

Prior to the orchiectomy, blood tests indicated Walborn had an elevated alpha-fetoprotein (AFP), a tumor marker, of 855 nanograms per milliliter (ng/mL). About a month after the