(CNN) - There's truth to online buzz that home pregnancy tests can detect some types of testicular cancer in men.

According to the American Cancer Society, pregnancy tests work by detecting a certain hormone.

That hormone is produced by the cells of a woman's placenta during pregnancy, but is also excreted by some, not all, testicular cancers.

The story originated with Internet reports of a teenage boy who took a home pregnancy test as a joke, received a positive result, and wound up being diagnosed with testicular cancer.

CNN