Noticing a strange lump on your body is always alarming. In the age of Dr. Google and rampant health anxiety, many of us immediately jump to the scariest possibility until proven wrong, which can lead to some anxiety-ridden hours (or days).

Tennis legend Serena Williams says she recently underwent surgery to remove a branchial cyst “the size of a grapefruit” from her neck.

The retired tennis star, who turned 43 last month, posted Wednesday on social media that she found a lump on her neck in May.