A dermoid cyst is an enclosed sac near the surface of the skin that forms during a baby’s development in the uterus. The cyst can form anywhere in the body. It may contain hair follicles, skin tissue, and glands that produce sweat and skin oil. The glands continue to produce these substances, causing the cyst to grow. Dermoid cysts are common. They’re usually harmless, but they need surgery to remove them. They don’t resolve on their own. Dermoid cysts are a congenital condition. This means they’re present at birth.

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 their reproductive years. They can cause torsion, infection, rupture, and cancer. 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.