These common, benign, solid, round or oval breast tumors are most common among women ages 15-35. They are rubbery in consistency, mobile and non-tender. They rarely grow larger than 2-3 cm.

The diagnosis is usually suspected on physical exam and confirmed with fine needle aspiration or excisional biopsy. When found in teenagers, they are often simply watched because of the very low risk of malignancy compared to the architectural disturbance caused by excisional biopsy.