What is an epidermal inclusion cyst? What does it look like?

An epidermal inclusion cyst is the most common cutaneous cyst. Epidermal inclusion cysts are also known as epidermal cysts, epidermoid cysts, infundibular cysts and keratin cysts.

Epidermal inclusion cysts are sometimes referred to as “sebaceous cysts,” however this is a misnomer as this lesion does not involve the sebaceous gland. The term “sebaceous cyst” should only be used in association with steatocystoma multiplex.

An epidermal inclusion cyst typically appears as a slowly enlarging, mobile, dome-shaped lump, filled with keratin material and located just below the surface of the skin. They can range in size from 0.5 cm to several centimeters. Often times, there is a “punctum,” or small dark-colored opening on the surface of the epidermal inclusion cyst, which connects to the cyst located below skin’s surface. Through the opening, the keratin material may be drained out. This should only be done by a dermatologist or other healthcare provider.

Epidermal inclusion cysts are generally considered benign (non-cancerous), although there have been rare cases of malignancy arising within the cyst.

Are epidermal inclusion cysts common?

Epidermal inclusion cysts are the most common type of skin cyst. They can be located anywhere, but are most common on the face, followed by the chest or back, scalp, neck, legs, arms and/or genitalia.

Are epidermal inclusion cysts painful?

Epidermal inclusion cysts are often asymptomatic. However as the keratin accumulates within the cyst, the cyst may increase in size, become sore or painful, and eventually rupture, leading to the drainage a foul-smelling, white to yellow “cheese-like” material. See your healthcare provider if you develop these or other concerning symptoms.

Are epidermal inclusion cysts cancerous?

Epidermal inclusion cysts are common and typically harmless, but rarely can become malignant (cancerous). Approximately 1% have been shown to transform into malignancy.

An epidermal inclusion cyst may concerning if it has any of the following characteristics:

• Signs of infection, including pain, redness, swelling and/or drainage.
• A fast rate of growth.
• A diameter larger than five centimeters.

It is difficult for the layman to tell whether a lump/growth is a cyst or something else. Please see your healthcare provider to ensure a correct diagnosis.

Who do epidermal inclusion cysts affect?

Although they can appear at any age, epidermal inclusion cysts most frequently occur during early to mid-adulthood (ages 20-60s). Epidermal inclusion cysts rarely appear before puberty. They are one and a half times more common in males than in females.

Are epidermal inclusion cysts contagious?

No, epidermal inclusion cysts are not contagious.

Are epidermal inclusion cysts permanent?

An epidermal inclusion cyst does not typically go away by itself completely unless removed surgically, by an excision. However, an epidermal inclusion cyst may shrink in size and stay asymptomatic for quite some time, and no treatment may be necessary.

What causes epidermal inclusion cysts?

Most epidermal inclusion cysts occur at random.

Some genetic conditions may be associated with the development of multiple epidermal inclusion cysts:

• Gardner Syndrome (Familial Colorectal Polyposis).
• Gorlin Syndrome (Basal Cell Nevus Syndrome).
• Favre-Racouchot syndrome.

Medications that may be associated with an increased the risk of developing epidermal inclusion cysts include:

• BRAF inhibitors.
• Imiquimod.
• Cyclosporine.

Epidermal inclusion cysts are formed from the follicular infundibulum, which is part of the hair follicle. Epidermal inclusion cysts form when the follicular infundibulum is disrupted, or when the surface of the skin becomes implanted below the skin through an injury or trauma in the area, such as a scratch, surgical wound or a skin condition like acne.

What are the symptoms of an epidermal inclusion cyst?

The main symptom of an epidermal inclusion cyst is a small moveable lump under the skin. The lump is usually not painful. In some cases, however, cysts can get inflamed and become tender to the touch. The skin on the area of the cyst may be red and/or warm.

Do certain foods worsen or improve an epidermal inclusion cyst?

No known foods or drinks affect epidermal inclusion cysts.

Is an epidermal inclusion cyst a sign of cancer?

Epidermal inclusion cysts are rarely harmful. However, there have been rare cases where malignancy has formed within the cyst. Discuss your concerns with your healthcare provider.

How long do epidermal inclusion cysts last?

Some cysts may decrease in size and become asymptomatic, while others continue to grow until you get treatment. Without treatment, you may have the epidermal inclusion cyst for the rest of your life.

How are epidermal inclusion cysts diagnosed?

Usually, your healthcare provider can diagnose an epidermal inclusion cyst with a simple examination of the skin. In some cases, the healthcare provider will perform a biopsy to rule out other skin growths.

What tests are done on epidermal inclusion cysts?

If your healthcare provider suspects that your epidermal inclusion cyst is, he or she may order the following tests:

• An ultrasound may help determine the contents of the cyst.
• A punch biopsy. This is where a small amount of the tissue from the cyst is removed and examined for signs of cancer.
• A CT scan may be helpful in confirming the diagnosis of a large epidermal inclusion cyst and help the surgeon determine the best plan for removal.

How are epidermal inclusion cysts treated?

In many cases, epidermal inclusion cysts can be left untreated and monitored, as they are not dangerous, and especially if they are not causing any symptoms.

If a cyst becomes inflamed or painful, your healthcare provider may consider treating the epidermal inclusion cyst with:

• Injection of steroid medication - to reduce swelling, which may help temporarily.
• Incision and drainage - your healthcare provider will make a small opening over the cyst and release the collection of drainage within the cyst.
• Surgical excision - The cyst is usually removed using an injection of local anesthetic to numb your skin. This procedure will leave a small line scar after the cyst is removed.

Do not try to burst and drain the cyst yourself, as it could cause and/or spread an infection, and the cyst will likely grow back.

What medications help with an epidermal inclusion cyst?

If you are concerned that your epidermal inclusion cyst is infected, you should contact your healthcare provider right away, as you may need antibiotics.

Is there a cure for an epidermal inclusion cyst?

Your healthcare provider may be able to drain the cyst, which may help temporarily, or they will refer you to a specialist to remove it surgically.

Are there complications or side effects of the treatment?

Risks of surgical excision of a cyst include a small chance of bleeding, infection and likely a small scar over the area where the cyst is removed.

Should I see a specialist?

Only certain healthcare providers can remove epidermal inclusion cysts. Your healthcare provider may refer you to a specialist who is trained to remove cysts, such as dermatologists and plastic surgeons.

Are there any at-home remedies that can help with epidermal inclusion cysts?

Warm compresses over the epidermal inclusion cyst may help to reduce inflammation and pain.

How can I reduce my risk of developing an epidermal inclusion cyst?

Epidermal inclusion cysts typically form spontaneously. However, avoiding trauma to the skin, and treating skin conditions that may cause injury to the skin, such as acne, may be helpful.

What medicines can I take to reduce my risk of epidermal inclusion cysts?

There are no medications that can prevent you from developing an epidermal inclusion cyst.

What foods should I avoid to reduce my risk of epidermal inclusion cysts?

What you eat and drink has no effect on epidermal inclusion cysts.

What can I expect if I’ve been diagnosed with an epidermal inclusion cyst?

Once you have been diagnosed with an epidermal inclusion cyst, you can wait and see if the cyst improves on its own, or may discuss treatment options with your healthcare provider.

How long will I have epidermal inclusion cyst?

Some cysts may decrease in size and become asymptomatic, while others continue to grow until you get treatment. Without treatment, you may have the cyst for the rest of your life.

Can epidermal inclusion cysts get worse?

Epidermal inclusion cysts sometimes remain small in size and asymptomatic for up to several years. However, they can also increase in size with time, and also may become uncomfortable or irritated, at which point, you should discuss treatment options with your healthcare provider.

What is it like living with an epidermal inclusion cyst?

Living with an epidermal inclusion cyst can vary, depending on how bothersome the cyst is. It can be challenging for some people, especially if the epidermal inclusion cyst is in a very visible location, such as the face or the scalp, or if it is painful.

How do I take care of myself if I think I may have an epidermal inclusion cyst?

Report your symptoms to your healthcare provider.

Never try to burst and drain the cyst yourself as it could cause and/or spread an infection, and the cyst could grow back.

Keep an eye out for signs of infection. Report them to your healthcare provider.

When should I see my healthcare provider about an epidermal inclusion cyst?

Always see your healthcare provider if you find a lump on your skin. It might be an epidermal inclusion cyst, another type of cyst, or something else. Don’t try to diagnose yourself. Don’t rely on the internet. See your healthcare provider for a clear diagnosis and specialized treatment.

What questions should I ask my healthcare provider about epidermal inclusion cysts?

• Do I have an epidermal inclusion cyst or another type of cyst?
• Do you think this will go away on its own, or will it need treatment?
• Do you think the epidermal inclusion cyst will get bigger?
• What treatment options do you recommend?
• Do I need to see a specialist or a surgeon?
• What should I do if the cyst comes back after the procedure?

A note from Cleveland Clinic

Please don’t hesitate to contact your healthcare provider, a dermatologist, or a plastic surgeon if you have any skin-related questions or concerns. Even if you are concerned for cosmetic reasons, that doesn’t mean you shouldn’t take care of your skin.

Be cautious. The lump on your skin might be a harmless, benign, epidermal inclusion cyst, or it may be a more serious diagnosis. Rely on your healthcare provider for a clear diagnosis and correct treatment options.