Cyst

This is an article about cysts in the body.

For the ICAO airport code CYST see St. Theresa Point Airport.

For hard-shelled resting stages of some small organisms, see encystment.

A cyst (soft "c", rhymes with "list") is a closed sac having a distinct membrane and develosion on the nearby tissue. They may contain air, fluids, or semi-solid material. A collection of pus is called an abscess, not a cyst. Once formed, the cyst will remain in the tissue permanently and can be removed by surgery and by taking medication that will dissolve the "sac".

A cyst may also be a sack that encloses an organism during a dormant period, such as in the case of certain parasites. This type of cyst may, for instance, protect a parasite from the churning acid of the stomach so it may pass through to the intestines unharmed where it can then break out. Cystic fibrosis is an example of a genetic disorder whereby cysts and fibrosis develop in the lungs.

Locations

Cysts can occur anywhere in the body; some of common ones are listed here:

• Chalazion cyst (eyelid)
• Cysticercal cyst (the larval stage of Taenia sp.)
• Dentigerous Cyst (associated with the crowns of non-erupted teeth)
• Epididymal Cyst (found in the vessels attached to the testes)
• Ganglion cyst (hand/foot joints and tendons)
• Glial Cyst (in the brain)
• Gartner's duct cyst (vaginal or vulvar cyst of embryological origin)
• Keratocyst (in the jaws, these can appear solitary or associated with the Gorlin-Goltz or Nevoid basal cell carcinoma syndrome. The latest World Health Organization classification considers Keratocysts as tumors rather than cysts)
• Meibomian cyst (eyelid)
• Nabothian cyst (cervix)
• Ovarian cyst (ovaries, functional and pathological)
• Paratubal cyst (fallopian tube)
• Pilonidal cyst (skin infection near tailbone)
• Renal cyst (kidneys)
• Radicular cyst (associated with the roots of non-vital teeth)
• Sebaceous cyst (sac below skin)
• Tarlov cyst (spine)
• Vocal fold cyst
• Dermoid cyst (Skull and ovaries)
• Breast cyst

Related structures

A pseudocyst is collection without a distinct membrane.

A syrinx in the spinal cord or brainstem is sometimes inaccurately referred to as a cyst.

External links

• Template:FPnotebook
• "Cyst Symptoms and Causes" by Melissa Conrad Stöppler, MD and William C. Shiel, Jr., MD, FACP, FACR.