A cyst is a closed sac
with a defined membrane and division on the nearby tissue. Cysts may contain
fluid, air or semi-solid material. There are various types of cysts, including
those on the skin, in breasts, on the ovaries or testes, kidneys or spine,
among others. A cyst may go away on its own or may require surgical removal.
Most often, cysts are benign tumors. However, these
masses may sometimes be considered neoplasms; for example, dermoid, keratocyst
or calcifying odontogenic cysts.
Cysts may be caused by defects during fetal development,
infections or unknown reasons. Suspicious cysts are often diagnosed using
needle aspiration. Fluids and substances drawn from the cyst are tested for
infection and evidence of uncontrolled cell growth. When surgery is not
indicated, physicians may prescribe antibiotics and pain-relieving medications.
Epidermoid and pilar cysts, which originate in the skin and hair follicles, may
cause lumps under the skin but often do not require surgical removal. Severe
cysts may require lancing, followed by treatment with sterile bandages and
antibiotics. Secondary infections after lancing are of concern until the cyst
has drained completely.
Parasites such as trichinosis, dog tapeworm and
echinococcus can form cysts within the muscles, liver, brain, lungs and eyes.
Additional information can be found by searching the following