Hi, Thanks for the query. The possible causes for the lump in the breast are : - Fibroadenoma, a benign growth in breast. -Fibrocystic disease can also present as small bumps. -Periductal mastitis sometimes can lead to formation of bumps. -Any injury to the breast can lead to formation of bruises etc. So as she is having pain, better to get examined. By examination and investigations like sonomammogram, the possible cause for the problem can be identified. If your doctor recommends, go for fine needle aspiration biopsy of the lump. Depending on the reports further management can be planned. Meanwhile she can take analgesic and anti inflammatory drugs to relieve the pain. Take care.