Brianna Kingsley had recently filed a lawsuit against William Wojciechowski in Detroit -- whom she was dating a couple years ago as she was transitioning ... and who she claims discarded her surgically-removed testicles in the wake of their breakup.

At first, Kingsley was suing Bill for allegedly not returning her balls to her -- claiming in her small claims suit that he was holding them hostage, and keeping them in a mason jar in his fridge next to a carton of eggs. However, after she sued him ... her ex countersued her, claiming she'd humiliated him and also noting that he'd already thrown the testicles away.

It was a lot of back and forth for a while ... and the absurd case was highlighted by a quote Kinglsey had said in court at one point -- saying, "We’re talking about my nuts … I wanted them in my fridge -- not his. The damages were the loss of these nuts."

Kingsley was seeking the return of her testes -- even though they'd already been thrown out -- plus an extra $6,500 in damages. The boyfriend was also seeking damages for his claim.

In the end ... hizzoner said the whole thing was ridiculous and not worth taking under further consideration -- in fact, he called their competing lawsuits against each other a "wash," and added that it would've been too difficult to put a dollar amount on balls.

The judge tossed both lawsuits and basically closed the book on this matter. He also noted his decision could not be appealed -- so no chance of either of them continuing to fight it.

BTW, Kingsley seemed proud to show off her balls a couple years ago after she underwent gender-reassignment surgery -- so we suppose it's understandable they were of value to her.