A dermoid cyst is a common, benign (non-cancerous), harmless growth that resembles a sac. The cyst develops on the fetus during pregnancy or it may grow on a baby soon after birth. It can grow on any part of the body, such as the head, face, or neck, but the most common is found around the eyes. Other common places for cyst formation include the orbit, the ovary, or the lower back region. A dermoid often develops close to the skin's surface and is easily noticed soon after the baby is born. However, some cysts may not be so obvious since they form deeper inside the body. These cysts comprise hair follicles, oil glands, teeth, sweat glands, fat, and fluid in or around the skin. Some cysts may contain nerves, teeth, or bone.
Types
Dermoid cysts fall into various categories based on location, which include:
Orbital dermoid cyst
This one is shaped like a mass of egg below the skin next to the eye socket’s bones. It's a smooth, painless, firm mass, and has an overlying skin with a normal appearance. The dermoid cyst may be attached to the bone or create a depression in the bone where it lodges. Sometimes, it may develop in front of the bones around the eye, especially the meeting point of the two facial bones that form the eye socket. Greasy, yellow material can fill the cyst
A periorbital dermoid cyst
A periorbital dermoid cyst is the most commonly occurring. It is congenital (present at birth) even though it may present a few years following a baby's birth. The cyst is often found on the eyebrow, either on the left or right. It rarely affects vision but may require treatment if infection sets in
Epibulbar dermoid cyst
Another type of orbital cyst affecting the eye is the epibulbar dermoid cyst located on the eye's surface. It can either be found at the intersection of the sclera and cornea (limbal dermoid) or where the eyelids meet towards the ear (lipodermoid). This cyst can also be found next to the nose
Other types
Other types of cysts that do not affect the eye include ovarian, spinal dermal cyst, brain, and sinus cysts
Causes & Risk Factors
The causes of dermoid cysts depend on the type. For instance, the cause of periorbital dermoid cysts is skin layers that fail to develop together as expected. The result is the development of a sac containing skin cells and other material near the skin's surface. The cyst continues to grow because of glands that do not stop to secrete fluid. Ovarian, spinal, and others also have their own individual causes.
Signs & Symptoms
One sign of a cyst is a small growth under the skin. Some dermoid cysts may present without symptoms. However, symptoms may manifest if the cyst grows significantly or gets infected. If the infection affects a periorbital dermoid cyst, it can lead to swelling near the skin’s surface. The skin develops a yellowish color, and the patient feels some discomfort. The cyst can also become red and spread infection if it bursts. Should the cyst occur on the face, inflammation around the eye area may follow. With a posterior epibulbar dermoid, the cyst typically has a yellow color and a soft consistency.
Diagnosis
Diagnosis of a dermoid cyst may involve the following:
Physical examination
Some cysts, such as a periorbital dermoid cyst, can be diagnosed through a physical exam. The doctor can move the cyst under the skin to get estimates of the shape and size. S/he examines the cyst and surrounding area
Imaging tests
If the doctor suspects that the cyst is located close to a sensitive area, s/he may order imaging tests. Sensitive areas include the neck's carotid artery, nerves, and eyes. These tests provide the cysts' precise location and information on the potential dangers of treating such a cyst. They help tell whether the cyst is attached to other head and neck tissue. Imaging tests include a CT scan, which provides comprehensive images of the cyst's location. The X-ray will show neck, face, head, or other body part images to capture the cyst's location. An MRI gives detailed pictures of body structures and organs.
Treatment
Surgical Treatment
A dermoid cyst rarely causes loss of vision and is not an emergency. However, it is removed if there is a risk of rupture and infection. Surgery is the only treatment option available and will depend on the age, symptoms, severity of the condition, and patient's health. It is easier to remove superficial cysts, but those that are in-depth in the skin need more expertise. During the operation, the surgeon opens the skin overlying the dermoid and dissects the tissues around until s/he can visualize the dermoid. The surgeon removes the cyst and sends it to the lab to identify the tissue. Depending on the cyst’s location, recovery may take at least two weeks.
Home Care
Home remedies to treat a dermoid cyst are forbidden. This is because attempts at self-removal can enable the cyst’s regrowth with chances of bleeding and infection. Untrained people may not distinguish a harmful from a harmless cyst.
Prognosis & Long-Term Outlook
A dermoid cyst is usually harmless and can be left untreated. It only causes problems when it ruptures, leading to infection. Cysts affecting the spine may injure it when they grow too large. Cyst removal is typically safe with few complications.
Prevention & Follow Up
Follow-up will depend on the type of cyst being treated.
