A breast lump (mass) is a thickening or bump that feels different from surrounding breast tissue. A lump may be discovered in a breast incidentally, during a breast self-examination, or during a routine physical examination by a doctor.
Lumps may be painless or painful. They are sometimes accompanied by nipple discharge or changes in the skin, such as irregularities, redness, a dimpled texture (called peau d'orange, or skin of an orange), or tightened skin.
Breast lumps may be fluid-filled sacs (cysts) or solid masses, which are usually fibroadenomas. Fibroadenomas are not cancerous, and cysts usually are not cancerous.