The Madchester singer was told by doctors that it was not cancerous, but he says it has now made him increasingly aware of his own mortality.
Ryder explained that the lump is causing him pain due to it pressing on a nerve, but he is yet to have it removed after the coronavirus outbreak resulted in the cancellation of thousands of non-essential operations.
He told The Sun: “This non-malignant growth in my testicle is pressing on a nerve. It’s like having really bad toothache in your balls.”
He added: “I was one of those dudes who never thought I could die, no matter what. I now think I’m not invincible.”
Ryder battled drug addiction during his time with the Happy Mondays, using crack cocaine, heroin and the tranquiliser temazepam, which led to the band’s break-up in 1992.
He has now been sober for 17 years, and previously credited cycling in helping him kick the addiction.
Earlier this year, Ryder said he believed he caught coronavirus at the start of the pandemic.
“I’m pretty sure we’ve had it. We had symptoms of it. I mean, nothing puts my missus in bed; no matter what, she’ll still get up even if she’s dying, but this floored her. She was in bed for over a week,” Ryder told Sky News.
The singer, who takes medication for an underactive thyroid and suffers from various allergies, explained that his battle with the disease could have been a lot worse.
“My immune system is pretty much shagged,” he said. “Once your thyroid’s gone, that’s it. My dust allergies are terrible as well. I get symptoms where I can’t swallow, I can’t breathe.
Despite being forced to cancel a string of shows as a result of the disease, Ryder said he was “all right” and joked that he “basically started self-isolating about 10 years ago, apart from work.”