Singer Michael Bolton, 70, will be taking a temporary break from touring following surgery to treat a brain tumor, according to a post he shared on Instagram and Facebook over the weekend.

The two-time Grammy winner best known for his soft rock ballads—and who appeared on The Masked Singer last year as Wolf—said he experienced “some very unexpected challenges” in 2023. “Just before the holidays, it was discovered that I had a brain tumor, which required immediate surgery,” he wrote. “Thanks to my incredible medical team, the surgery was a success.”

“It is always the hardest thing for me to ever disappoint my fans or postpone a show but have no doubt I am working hard to accelerate my recovery and get back to performing soon,” Bolton wrote, thanking fans for their love and support since he started recording music in 1975. His latest album, Spark of Life, was released in July.

The majority (81.7%) of brain tumors occur in adults older than 40, and about 72% of all brain tumors are benign, according to the American Brain Tumor Association. In fact, it is estimated that about 79,300 adults over 40 were diagnosed with a primary brain tumor last year in the United States. What’s more, the five-year relative survival rate for all patients with a primary brain tumor is 76%.

The “How Am I Supposed to Live Without You?” singer did not say whether the brain tumor was cancerous or why emergency surgery was needed.

Treatment for a brain tumor depends on its grade, but many people undergo surgery requiring a craniotomy, a surgical procedure in which part of the skull is temporarily removed to access the brain and the tumor is biopsied for diagnosis.

Tiny Pretty Things actor Barton Cowperthwaite, 31, for example, recently underwent a successful craniotomy to treat a lemon-sized tumor in his brain that likely had been there for five to 10 years.

Bolton thanked fans for their positivity and generosity over the years and assured them he would be performing onstage as soon as possible.

“Know that I’m keeping your positive messages in my heart, and I’ll give you more updates as soon as I can,” he concluded. “Much love always, MB.”

To read more on this topic, click #Brain Tumor. There, you’ll find headlines such as “Tiny Pretty Things Actor Had Operation to Treat ‘Lemon-Sized’ Brain Tumor,” “Brain Cancer Patient and Endurance Athlete Is Ready for the Fight of His Life” and “Engaging People with Low-Grade Glioma in Cancer Research.”