Light micrograph section through human female breast tissue showing breast fat necrosis. Breasts are mostly made up of fatty tissue and if that is damaged by injury, surgery or radiotherapy, a lump can form, called fat necrosis. This is a benign condition and does not increase the risk of developing breast cancer. It can occur anywhere in the breast and can affect women of any age. Men can also get fat necrosis, but it is very rare.