Former tennis champion Serena Williams revealed on Wednesday that she had a non-cancerous branchial cyst taken out from her neck.

The 43-year-old athlete shared on social media that the cyst was “the size of a small grapefruit” and reassured fans that she was “doing well.”

Williams mentioned that the cyst was discovered in May and posted a video showing herself recovering in a hospital bed.

“They informed me I didn’t have to have it removed if I didn’t want to,” Williams stated. “I chose not to initially, but it kept growing. I underwent more tests, including three exams and one biopsy, all of which were negative. Doctors eventually advised me to have it removed as soon as possible because of its size and the potential for infection or leakage.”

In a follow-up post, Williams updated fans, saying she was “still on the mend, but improving. Health always comes first.”

Throughout her illustrious tennis career, Williams secured 23 singles Grand Slam titles and another 14 in doubles. She held the No. 1 spot in the WTA rankings for a record 319 weeks, earned four Olympic gold medals, and was named Associated Press Athlete of the Year five times.