What are some common types of benign breast lumps? Noncancer (benign) breast lumps can have many causes. Two of the most common causes of benign single breast lumps are cysts and fibroadenomas.
But most new lumps — more than 90% — are benign, or noncancerous. Watch for any breast changes and report them to your doctor right away. The earlier breast cancer is detected, the better your ...