From the question: Could a man be proved positive for a pregnancy test?. I don't mean if a man could be pregnant but if he runs a pregnancy test, it is possible for it to come out positive?
Pregnancy test, just like any test, has some non-zero false positive rate. So yes, of course a test could be positive when a man pees on it.
Pregnancy tests work by detecting the presence of a hormone called Beta-HCG. This hormone is produced by both genders but is produced in much higher dose during early pregnancy. Teenagers also produce a relatively high dose of Beta-HCG which can eventually inflate the false positive rate.
It just so happen that tumours from a particular type of testicular cancer also excrete Beta-HCG (see this blog post from the American Cancer Society). If your question arises from a personal experience, then I would strongly recommend that you talk about it with your doctor.
Yes it is possible. Pregnancy tests detect human chorionic gonadotropin (hCG), which in a healthy male can be produced by the pituitary gland. hCG consists of two subunits and the urine tests target a metabolite of the beta subunit. The levels of hCG in healthy adult males are below the sensitivity of pregnancy tests, they are similar to the hCG levels in non-pregnant adult females.
A postive test from a male may indicate a pathology that is elevating hCG. I know that hCG elevates during puberty but I am not sure whether the rise is sufficient to cause a positive pregnancy test.