Dermoid cysts are growths that can affect areas of the body, including the nasal sinuses, ovaries, brain and spinal cord.
A dermoid cyst is present at birth, but may not be noticeable until much later. It contains structures such as hair, fluid, teeth or skin glands that can be found on or in the skin.
Dermoid cysts grow slowly and are not tender unless ruptured. They usually occur on the face, inside the skull, on the lower back and in the ovaries. Superficial dermoid cysts (ones near the surface of the skin) on the face can usually be removed without complications. Removal of other, rarer dermoid cysts requires special techniques and training. These rarer dermoid cysts occur in four major areas:
- Dermoid cysts in the brain: Dermoid cysts occur very rarely here. A neurosurgeon may need to remove them if they cause problems.
- Dermoid cysts in the nasal sinuses: These are also very rare. Only a handful of cases involving dermoid cysts located here are reported each year. Removal of these cysts is extremely complicated.
- Ovarian dermoid cysts: These growths can develop in a woman during her reproductive years. They can cause torsion (twisting), infection, rupture and cancer of the ovary. These dermoid cysts can be removed with either conventional surgery or laparoscopy (surgery that uses small incisions and specially designed instruments to enter the abdomen or pelvis).
- Dermoid cysts of the spinal cord: A sinus tract, which is a narrow connection from a deep pit in the skin, usually connects these very rare cysts to the skin surface. This type of dermoid cyst can become infected. Removal is often incomplete, but the outcome is usually excellent.
Dermoid cyst causes
Dermoid cysts are caused when skin and skin structures become trapped during foetal development (the early stages of growth of the baby in the womb). Their cell walls are nearly identical to those of the outer skin and may contain multiple skin structures such as hair follicles, sweat glands and sometimes hair, teeth or nerves.
When to seek medical care
Medical advice should be sought in the following situations:
- A cyst becomes painful or inflamed.
- A cyst grows or changes colour.
- Removal is desired for cosmetic reasons - but this may not be available on the NHS.
Typically, removing a dermoid cyst is not an emergency procedure. If a dermoid cyst ruptures, becomes inflamed, or causes pain or fever, a person should seek immediate medical advice.
Examinations and tests
Prior to removal of superficial dermoid cysts on the face, a person should know the difference between cysts and other facial growths.
- Because dermoid cysts stem from birth and grow slowly, a person usually notices them during childhood or early adulthood.
- Dermoid cysts are firm and painless unless ruptured.
- Dermoid cysts are not attached to the overlying skin.
In rare cases, a dermoid cyst extends into a structure deeper than skin, such as a facial cavity (sinus) or an orbit ( eye-socket). Some doctors recommend a CT-scan (specialised X-ray) or other imaging studies for these cases.