(See also Overview of Breast Disorders Overview of Breast Disorders Breast disorders may be noncancerous (benign) or cancerous (malignant). Most are noncancerous and not life threatening. Often, they do not require treatment. In contrast, breast cancer can mean... read more and Breast Lumps Breast Lumps 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... read more .)
Breast cysts are common. In some women, many cysts develop frequently, sometimes with other fibrocystic changes Fibrocystic Changes of the Breast Fibrocystic changes of the breast (formerly called fibrocystic breast disease) include breast pain, cysts, and lumpiness that are not due to cancer. (See also Overview of Breast Disorders and... read more . The cause of breast cysts is unknown, although injury may be involved.
Breast cysts can be tiny or several inches in diameter.
Cysts sometimes cause breast pain Breast Pain Many women experience breast pain. Breast pain may occur in one or both breasts. (See also Overview of Breast Disorders.) Likely causes of breast pain depend on whether the pain is felt in a... read more . To relieve the pain, a doctor may drain fluid from the cyst with a thin needle (called aspiration). The fluid is examined under a microscope to check for cancer only if any of the following occurs:
The fluid is bloody or cloudy.
Little fluid is obtained.
The lump is still present after the fluid is drained.
Otherwise, the woman is checked again in 4 to 8 weeks. If the cyst can no longer be felt at this time, it is considered noncancerous. If it has reappeared, it is drained again, and the fluid is examined under a microscope. If the cyst reappears a third time or if it is still present after it was drained, a biopsy is done.
Rarely, when breast cancer Breast Cancer Breast cancer occurs when cells in the breast become abnormal and divide uncontrollably. Breast cancer usually starts in the glands that produce milk (lobules) or the tubes (ducts) that carry... read more is suspected, cysts are removed.