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File:Simple cyst, kidney.jpg
Benign cyst kidney; radiological appearances mimic renal cancer,

A cyst Template:IPAc-en is a closed sac, having a distinct envelope and division compared with the nearby tissue. Hence, it is a cluster of cells that have grouped together to form a sac (like the manner in which water molecules group together to form a bubble); however, the distinguishing aspect of a cyst is that the cells forming the "shell" of such a sac are distinctly abnormal (in both appearance and behaviour) when compared with all surrounding cells for that given location. A cyst may contain air, fluids, or semi-solid material. A collection of pus is called an abscess, not a cyst. Once formed, a cyst may resolve on its own. When a cyst fails to resolve, it may need to be removed surgically, but that would depend upon its type and location.

Cancer-related cysts are formed as a defense mechanism for the body following the development of mutations that lead to an uncontrolled cellular division. Once that mutation has occurred, the affected cells divide incessantly and become cancerous, forming a tumor. The body encapsulates those cells to try to prevent them from continuing their division and contain the tumor, which becomes known as a cyst. That said, the cancerous cells still may mutate further and gain the ability to form their own blood vessels, from which they receive nourishment before being contained. Once that happens, the capsule becomes useless, and the tumor may advance from benign to cancerous.

Some cysts are neoplastic, and thus are called cystic tumors. Many types of cysts are not neoplastic, they are dysplastic or metaplastic. Pseudocysts are similar to cysts in that they have a sac filled with fluid, but lack an epithelial lining.

TerminologyEdit

  • microcyst – a small cyst that requires magnification to be seen
  • macrocyst – a cyst that is larger than usual or compared to others

Related structuresEdit

A pseudocyst is very similar to a cyst, but is a collection of cells without a distinct membrane (epithelial or endothelial cells).

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

Cysts by locationEdit

Female reproductive systemEdit

File:Relative incidences of ovarian cysts.jpg
Relative incidences of different types of ovarian cysts<ref name="AbduljabbarBukhari2015">Template:Cite journal</ref>

Male reproductive systemEdit

Cutaneous and subcutaneousEdit

Head and neckEdit

ChestEdit

AbdomenEdit

Central nervous systemEdit

Musculoskeletal systemEdit

Seen in various locationsEdit

Infectious cystsEdit

  • Cysticercal cyst – an infection due to the larval stage of Taenia sp. (Crain's backs)
  • Hydatid cyst – an infection in the liver or other parts of the body due to the larval stage of Echinococcus granulosus (tapeworm)

Neoplastic cystsEdit

TreatmentEdit

Treatment ranges from simple enucleation of the cyst to curettage to resection. There are cysts—e.g., buccal bifurcation cyst—that resolve on their own, in which just close observation may be employed, unless it is infected and symptomatic.<ref name="BBC">Template:Cite journal</ref>

Cystic fibrosisEdit

Despite being described in 1938 as "the microscopic appearance of cysts in the pancreas",<ref name=Andersen1938>Template:Cite journal</ref> cystic fibrosis is an example of a genetic disorder whose name is related to fibrosis of the cystic duct (which serves the gallbladder) and does not involve cysts.<ref>Template:Cite journal</ref>

This is just one example of how the Greek root cyst-, which simply means a fluid-filled sac, also is found in medical terms that relate to the urinary bladder and the gallbladder, neither of which involve cysts.

See alsoEdit

ReferencesEdit

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External linksEdit

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