You may have seen the headline, or maybe you’re one of the 1.7 million-and-counting people who clicked on the Reddit post that started it all.

Here’s the story: A guy found his ex-GF’s pregnancy test in his medicine cabinet, took the test for laughs, and found out he was pregnant.

At least that’s what the test said. It seemed funny, so a friend of his posted a cartoon of the story on Reddit. Comments to the post noted that pregnancy tests identify hCG, a hormone produced during pregnancy — and in testicular cancer.

Sure enough, the man found he had a small tumor in one of his testicles. A follow-up post says it was a very early, curable tumor.

Does all this make sense? I asked Bruni Nazario, MD, WebMD’s resident endocrinologist.

“Yes, this is possible. Testicular cancer makes hormones and one hormone produced is hCG, the same hormone produced by embryonic tissue during pregnancy. This cancer also produces AFP, a fetal protein measured during pregnancy.”

If a man gets a positive result on a pregnancy test, does it always mean testicular cancer?

No, Nazario says. HCG is not unique to testicular cancer. Other cancers can also produce these hormones.

Many of the comments to the Reddit post are from men who now are considering giving themselves pregnancy tests. But that isn’t a good idea.

Although testicular cancer is the most common cancer in men age 15 to 34 years, it’s pretty darn rare. There are only 5.4 cases per 100,000 men each year.

On the other hand, false-positive tests are common. Widespread pregnancy testing of men would mean a lot of unnecessary worry — and a lot of unnecessary diagnostic tests and procedures, which carry their own small risks.

In fact, the U.S. Preventive Services Task Force (USPSTF), the expert panel that advices the U.S. on screening tests, recommends against routine testicular cancer screening.

Most testicular cancers are self-detected, or detected by a sex partner. There’s no evidence that regular self-exams or doctor exams catch these cancers any earlier. And even in advanced testicular cancer, cure rates are quite high.

Treatment of testicular cancer means removal of the affected testicle or testicles. It may include other surgery, radiation therapy, and chemotherapy.

“Regardless of disease stage, more than 90% of all newly diagnosed cases of testicular cancer will be cured,” the USPSTF notes.