Such a lump could result from an injury, infection
, cyst or fibrocystic change. If you had previous breast
injuries, fat cells in
tissue may be damaged and produce a firm, painful lump in the breast. If lumps are accompanied by breast tenderness and redness, it may suggest an infection. Similarly, breast cysts can also produce firm, tender lumps in the breast that change in size and seem to appear and disappear as your monthly hormone levels change.