Give a constant wisecracker a very scary brain tumor and you get a book that begins:

“If you’re reading this, it means I’m already dead.

“Just kidding. I’m not dead. (Spoiler alert.) I’ve just always wanted to say that.”

In 2009, Bryan Bishop was 30 years old, engaged to be married and happily working as the sidekick on comedian Adam Carolla’s radio show and podcast. Then a doctor who sounded “as if he had memorized a worksheet titled ‘Good Bedside Manner’ the night before” told Bishop he had an inoperable brain tumor and probably would live six months to a year.

Shrinkage: Manhood, Marriage and the Tumor That Tried to Kill Me” is the story of what happened next, told in dude-style prose just waiting to be filmed by Judd Apatow. Bishop’s bachelor party inspires him to wonder, “I can’t be the first guy to take chemo in a strip club, can I?” and one section on the effects of chemotherapy begins, “Just a heads-up: I’m about to describe my feces.”

In "Shrinkage,” comedian Bryan Bishop deals with a serious illness. (Thomas Dunne Books)

When he’s so weak that a therapist has to get into the shower to show his wife how to bathe him, he can only think “threesome.”

But this isn’t just a series of juvenile jokes: Bishop writes powerfully about the frightening reality of his disease and the desperate search for treatment. Occasionally he offers a “Tumor Tip” that gives advice in refreshingly plain, readable language. “Don’t do what I did and insist upon telling all your loved ones about your diagnosis personally,” he says: It takes too long, and friends who hear about it before you get to them are hurt.

Scene after scene is both sad and funny: Not long before their wedding, his fiancee loses the diamond from her engagement ring when she joins him on a visit to Cedars Sinai Medical Center in Los Angeles.The contraption that holds his head still for radiation looks like a death mask made from a melted tennis racket, and the radiologist urges him to personalize it with decorations.

A key moment in recovery happens in the Costco personal care aisle, when he gambles on living long enough to buy the 20-count package of razor blades. Jimmy Kimmel writes the cover blurb, which, like a lot of the jokes, can’t be printed in a family newspaper.