What is a cyst?
A cyst is a closed, saclike structure that contains fluid, gas, or semisolid material and is not a normal part of the tissue where it is located. Cysts are common and can occur anywhere in the body in people of any age. Cysts vary in size; they may be detectable only under a microscope or they can grow so large that they displace normal organs and tissues. The outer wall of a cyst is called the capsule.
What are the causes of a cyst?
Cysts can arise through a variety of processes in the body, including
- "wear and tear" or simple obstructions to the flow of fluid,
- infections,
- tumors,
- chronic inflammatory conditions,
- genetic (inherited) conditions,
- defects in developing organs in the embryo.
Most cysts arise due to the types of conditions listed above and are only preventable to the extent that the underlying cause is preventable.
What are the signs and symptoms of a cyst, and how are they diagnosed?
Sometimes you can feel a cyst yourself when you feel an abnormal "lump." For example, cysts of the skin or tissues beneath the skin are usually noticeable. Cysts in the mammary glands (breasts) also may be palpable (meaning that you can feel them when you examine the area with your fingers). Cysts of internal organs such as the kidneys or liver may not produce any symptoms or may not be detected by the affected individual. These cysts often are first discovered by imaging studies (
X-ray,
ultrasound, computerized tomography or
CAT scan, and
magnetic resonance imaging or MRI). Cysts may or may not produce symptoms, depending upon their size and location.
