The Olympic gold medalist, 51, is "resting comfortably in the hospital" with his wife, Tracie, by his side. "The priority is for him to rest and recover so he can get home to his boys," Aidan and Maxx, his rep tells PEOPLE.
Hamilton had the surgery in Boston on Wednesday and will remain in the ICU for a few days before he is expected to return home next week.
The figure skater, who underwent chemotherapy for testicular cancer in 1997, discovered the benign tumor in 2004. Called craniopharyngioma, the tumor could have caused blindness if left untreated.
Reporting by LORENZO BENET