- Non-cancerous Breast Conditions
- What is normal breast tissue and what does it do?
- Finding benign breast conditions
- American Cancer Society recommendations for early breast cancer detection
- Diagnosing benign breast changes
- Imaging tests for breast disease
- Nipple discharge exam (nipple smear)
- Types of non-cancerous breast conditions
- Fibrosis and simple cysts
- Lobular carcinoma in situ
- Phyllodes tumors
- Intraductal papillomas
- Granular cell tumors
- Fat necrosis and oil cysts
- Duct ectasia
- Other benign breast conditions
- How benign breast conditions affect breast cancer risk
- For women at increased breast cancer risk
- Additional resources
Fat necrosis and oil cysts
Fat necrosis happens when an area of the fatty breast tissue is damaged, usually as a result of injury to the breast. It can also happen after surgery or radiation therapy. As the body repairs the damaged tissue, it is replaced by firm scar tissue.
Because most breast cancers are also firm, areas of fat necrosis with scarring can be hard to tell from cancers by a breast exam. It may also be hard to tell the difference on a mammogram. A needle biopsy, or sometimes an excisional biopsy, may be needed to learn if cancer is present.
Fat necrosis is more common in women with very large breasts. It does not increase a woman's risk of developing breast cancer.
Some fat cells may respond differently to injury. Instead of forming scar tissue, the fat cells die and release their contents. This forms a sac-like collection of greasy fluid called an oil cyst. Oil cysts can be diagnosed by fine needle aspiration. This can also serve as treatment, but it is not usually needed unless the cyst is bothersome.
Last Medical Review: 08/24/2012
Last Revised: 08/24/2012