Although widespread use of screening mammography has increased the number of breast cancers found before they cause any symptoms, some breast cancers are not found by mammography, either because the test was not done or because even under ideal conditions mammography cannot find every breast cancer. The most common sign of breast cancer is a new lump or mass. A mass that is painless, hard, and has irregular edges is more likely to be cancerous, but some rare cancers are tender, soft, and rounded. For this reason, it is important that any new breast mass or lump be checked by a health care provider with experience in diagnosis of breast diseases. Other signs of breast cancer include a generalized swelling of part of a breast (even if no distinct lump is felt), skin irritation or dimpling, nipple pain or retraction (turning inward), redness or scaliness of the nipple or breast skin, or a discharge other than breast milk. Sometimes a breast cancer can spread to underarm lymph nodes that are obviously enlarged, even before the original tumor in the breast tissue is large enough to be felt. | 
