 A breast lump is a localized swelling, bulge or bump in the breast that feels different from the breast tissue around it or the breast tissue in the same area of the other breast. There are different reasons why breast lumps develop and most lumps are harmless and not cancerous. While it is worth seeing a doctor about any breast lump, most benign breast lumps do not require treatment. Upon a physical examination, the doctor may recommend a mammogram or ultrasound scan to check what kind of lump is present. If there is a cyst or a fibrous lump, they may recommend monitoring the lump without taking any further action. If there is an abscess, the doctor may drain it with a fine needle and prescribe medications. If the doctor suspects cancer, a biopsy may be taken. If cancer is found, treatment usually involves surgery and chemotherapy or radiation therapy.