Rafael Lovato Jr. relinquished the Bellator middleweight title due to ongoing medical complications, the promotion announced Monday.
"I dreamed of having a long reign as champion, but sometimes life has another plan," Lovato said in a press release. "Bellator has been very supportive during this difficult process, a situation that has never really happened before in our sport. I know the division must move on while I am on the sidelines and I wish everyone great fights on their way to that belt."
Lovato revealed in January that he was diagnosed with a cavernoma, a hereditary condition that involves "abnormally formed blood vessels" usually found in the brain or spinal cord.
Bellator will announce plans for the vacant belt "in the coming days," according to the release.
Lovato won the title last June against Gegard Mousasi by majority decision. The undefeated fighter is 6-0 in Bellator.
The Brazilian jiu-jitsu ace is scheduled to compete in a grappling match later this month.
"I will be working to come back if it is possible - and if not, life will continue to be amazing for me and I look forward to working with Bellator in another fashion," Lovato said.