Hello and welcome. Antibiotics would help if it is a breast abscess, which seems unlikely. The more likely condition is called fibroadenoma, which is a benign breast growth also called the mouse tumor. They are completely harmless and women live with them all their lives. Of course we need to confirm the same, so please go ahead with a mammogram of the breasts for a confirmation, especially if the antibiotics do not help reduce the size. Also, write to me using our premoum service so I can guide you better. Best wishes.