What is a cyst?
Cysts are small cavities that have a lining membrane and contain
fluid or semisolid material or air. They may occur as a result of a
developmental error in the embryo before birth, or they may be caused
by an infection, or, in some cases, they arise spontaneously and no
cause is found.
Cysts can occur in almost any organ in the body. Sometimes they
are an incidental finding when an ultrasound or CT scan is done for
another reason and may never cause any problems. Such cysts are
commonly seen in organs such as the liver, pancreas or kidney. A
single cyst is likely to be an innocent finding, but multiple cysts,
especially in the kidneys, can be indicative of polycystic kidney
disease and may lead to renal problems.
A few of the more common or important cysts are described
1) Ovarian Cyst
An ovarian cyst is a fluid-filled sac in the ovary. It is most
often normal, occurring as a result of ovulation; these are called
'functional cysts' and will normally shrink over time. They may
occasionally cause pain if they rupture, or continue to grow, or if
they bleed. They are usually demonstrated by ultrasound
The management of an ovarian cyst depends on its size,symptoms
whether there are solid areas, the age of the person and blood test
results(CA125). In younger (pre menopausal women) with smaller benign
cysts a follow up scan in 3-6 months to check that they have gone is
a common strategy.
In post menopausal women,earlier investigation with aspiration and
possibly biopsy is a safer strategy to ensure early ovarian cancer is
A ganglion is a fluid-filled cyst that is connected to a joint or
the 'tunnel' that surrounds finger tendons. They tend to occur on the
back of the wrist or hand. The majority of these do not cause any
pain or functional problem and can be left alone. They can sometimes
even disappear spontaneously.
Occasionally they cause problems by pressing on a nerve and, in
these cases, it is necessary to surgically remove the ganglion.
Sometimes they are removed for cosmetic reasons,particularly if they
are causing an unacceptable lump in an exposed area,
Ganglion surgery can often be done under local anaesthetic, but
larger cysts, especially those on the wrist, may need a general
3) Baker's cyst
A "baker's cyst" appears as a swelling behind the knee, and is
often associated with osteoarthritis of the knee joint. It is caused
by a defect in the fibrous capsule that surrounds the joint and is
filled with joint (synovial) fluid. If it causes persistent symptoms,
a Baker's cyst can be surgically removed.
4) Sebaceous cysts
These cysts occur in the skin in adults, typically on the trunk,
neck, face or scalp. They are dome-shaped, appear whitish or
skin-coloured and are filled with keratin, a semisolid compound that
is the main component of hair, nails and skin.
They are usually painless, but may become red and painful if
injured or infected. They are usually easily removed under local
5) Branchial and thyroglossal cysts
These cysts, which are uncommon, present as lumps in the neck.
They are both a result of an error in embryonic development (before
birth), but may appear only in adulthood.
Branchial cysts are filled with fluid containing cholesterol
crystals. They appear on the front of the neck, on either side of the
Thyroglossal cysts appear as a swelling in the midline of the
neck, in front. They move on protruding the tongue.
Both of these types of cysts are treated by surgical removal.
6) Breast cysts
Lumps in the breast may be caused by 'fibrocystic change'. These
small cysts (1 to 5cm in diameter) may occur on their own and be
difficult to distinguish from a malignant breast lump, but, more
often, they are multifocal and often affect both sides. They may be
painful and tender at certain times in the menstrual cycle.
You should always see a doctor if you detect any sort of breast
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