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Symptoms and Signs of Breast Cancer vs. Cyst Differences and Similarities

Doctor's Notes on Breast Cancer vs. Cyst Differences and Similarities

Breast cancer is the abnormal growth, development, and spread (metastasize) of breast tissue. A cyst is a thin-walled hollow cavity usually containing a fluid. Most breast cysts are not cancerous and do not contain cancer cells, although a few may (complex cysts). Some cysts may self-resolve, but breast cancer does not. Early breast cancer and small cysts may have no symptoms, but as breast cancer advances, lumps, breast discharge, nipple inversion, and breast skin changes may occur. If a cyst produces signs or symptoms, it may cause redness, swelling, or tenderness at the site. A doctor should investigate all breast cysts carefully to rule out breast cancer.

The root cause of breast cancer development is unknown, but it occurs in women mainly and may be related to hormonal changes, alcohol consumption, diet, and other factors. The same is true for the cause of breast cyst development although some evidence suggests that excess estrogen may contribute to their development.

Medical Author:
Medically Reviewed on 6/3/2019


Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.