Cysts

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Cyst facts

  • Cysts are closed sac-like or capsule structures that may be filled with semisolid material, gaseous material, or liquid.
  • There are several causes of cysts, including genetic, infectious, and other causes that result in hundreds of types of cysts.
  • Risk factors for developing a cyst are related to the underlying causes of the cyst formation.
  • The majority of cysts are asymptomatic and have no signs; however, some cysts on the skin, mucous membranes, and those located in palpable organs often can be felt as a lump or bump; sometimes they are painful.
  • Some cysts may produce symptoms related to the organs in which they are located (for example, liver, pancreas, or kidneys).
  • It's possible to diagnose cysts by palpation, ultrasound, X-rays, CT scans, MRI scans, and needle biopsies.
  • Most cysts do not require treatment, however, physicians may use needle aspiration or surgical removal to treat some cysts.
  • The prognosis for most cysts is good; a few cysts that contain malignant cells have a more guarded prognosis.
  • Most cysts are not preventable; those that are preventable are usually related to infectious causes.

What is a cyst?

A cyst is a closed capsule or sac-like structure, usually filled with liquid, semisolid, or gaseous material. Cysts usually occur within a body's tissue; they vary in size from microscopic to large structures that can displace internal organs. Although "cysts" can also refer to any normal bag or sac formation in the body, in this article, we will use the definition stated above and consider it to be an abnormal formation. Consequently, the cyst is not a normal part of the body. It has a distinct membrane or cyst wall. If the sac is filled with pus, it is usually considered an abscess, not a cyst.

Medically Reviewed by a Doctor on 2/13/2014

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Pilonidal Cysts: What Are the Risk Factors?

Pilonidal cysts arise at the base of the tailbone (coccyx) of the lower back, just above the natal cleft (the cleavage between the buttocks). Doctors sometimes use the term pilonidal disease to refer to the range of problems that can affect this area. In simple cases, a small, solitary cyst-like area containing fluid is present without evidence of infection.