There are a variety of breast diseases, ranging from infections to excessive cell growth (neoplasms). Unfortunately, many breast diseases mimic the symptoms of cancer and therefore require tests and possibly surgical biopsy to obtain an accurate diagnosis. The majority of biopsies are found to be benign (non-cancerous) forms of breast disease. While most breast diseases are not dangerous in themselves, they may increase the risk of developing breast cancer. Hyperplasia, cysts, fibroadenomas, and calcifications are the common benign breast diseases.
Calcifications are randomly scattered residues of calcium that in older women may have left the bones to appear in other parts of the body, such as the joints or breasts. Microcalcifications are small, tight clusters of tiny calcifications in the ducts that can be seen on a mammogram and may indicate a precancerous or cancerous condition.
Cysts are sacs filled with fluid; they are almost always benign. Although most are too small to feel, approximately a third of women between the ages of 35-50 have cysts in their breasts. If large enough, cysts may feel like lumps in the breast. Normally, cysts are left untreated. However, if a cyst becomes painful, it can be aspirated or drained of its fluid. Some women may prefer to have a cyst removed if, after being aspirated repeatedly, it continues to recur.
Cysts are not associated with an increased risk of cancer; yet, they are more common in women as they approach menopause and occur much less frequently after menopause (Donegan 1995). What causes cysts to develop is unknown; however, certain dietary factors, such as the intake of caffeine have been proposed as possible risk factors for the development of breast cysts.
Fibroadenomas are a type of benign lump most commonly found in younger women. They are usually not removed since they pose no risk. If a fibroadenoma is large, uncomfortable, and produces a lump, it may be removed. In older women, fibroadenomas are generally removed to ensure that they are not malignant tumors. Fibroadenomas do not pose an increased risk of cancer.
Hyperplasia is not a precancerous condition. It is the excessive accumulation or proliferation of normal cells typically found on the inside of the lobules or the ducts in the breast tissue. Hyperplasia is associated with approximately a two-fold risk of breast cancer.
Atypical hyperplasia occurs when excess cells in the lobules or ducts are abnormal. This condition falls between hyperplasia (too many normal cells) and carcinoma in situ (too many abnormal cells). However, atypical hyperplasia is associated with an approximately 3.5-5 times increased risk of developing breast cancer (Page et al. 1985; Colditz 1993; Marshall et al. 1997).