Cyst

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A cyst is a sac-shaped structure in the body. Cysts usually are filled with fluid, which may be blood, clear fluid, or pus.

A cyst can be normal, abnormal, or, in rare cases, cancerous. In some cases, a cyst may be drained either with a needle or by cutting it open, or it may be removed entirely.

The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.