Back in November 2012, a Reddit user with the screen name ‘CappnPoopdeck’ posted a humorous rage comic to that site, one that detailed the experiences of a male friend who had jokingly taken a pregnancy test left in his medicine cabinet by an ex-girlfriend and surprisingly obtained a positive result:

Although the post was intended as nothing more than a joke, the responses on Reddit soon took a serious turn, with CappnPoopdeck being advised, “If this is true, you should check yourself for testicular cancer. Seriously. Google it.”

In fact, it turned out that pregnancy tests will record a positive result upon the detection of the hormone human chorionic gonadotropin (HCG), which is produced not only by pregnant women but also by some men with testicular tumors. CappnPoopdeck posted a follow-up comic informing Redditors that her friend had visited a doctor and found a small tumor in his right testicle (caught early enough to be treated immediately), and she thanked them for their helpful advice:

However, although a home pregnancy test may be able to detect some forms of testicular cancer, this Redditor’s experience should not be taken to mean that such tests are a reliable method of detecting that disease. As the American Cancer Society has noted, they reliably apply in only a small minority of testicular cancer cases:

Just because the test helped this man get a positive cancer diagnosis doesn’t mean it’s a reliable tool everyone should use, according to the American Cancer Society.The organization put the question to Ted Gansler, director of medical content, who wrote that “only a small minority of men” with testicular cancer have HCG levels high enough to be detected by a home pregnancy test. He added that “several non-cancerous conditions can cause false positive results.” According to Gansler, “current evidence does not indicate that screening the general population of men with a urine test for HCG (or with urine or blood tests for any other tumour marker) can find testicular cancer early enough to reduce testicular cancer death rates.” One thing men can do is be on the lookout for lumps in the testicles and see your doctor if you find one. Testicle pain or swelling and heaviness or aching in the lower abdomen are also possible signs of testicular cancer.

In February 2014, a 21-year-old student also discovered he had testicular cancer, and obtained a potentially life-saving diagnosis, due to information about the disease he found on Reddit: