Serena Williams says she had a benign branchial cyst “the size of a small grapefruit” removed from her neck and “all is OK.” The retired tennis star, who turned 43 last month, posted Wednesday on social media that she found a lump on her neck in May, had an MRI exam, and was told she didn’t need to get it removed if she didn’t want to. After more tests, including a biopsy that was negative for cancer, Williams said, her doctors said she should have a procedure.