What is a sebaceous cyst? What does it look like?
A cyst is a slow-growing, protein-filled, dome-like, yellow or white lump that can move easily under the skin. There are many types of cysts – hundreds, actually. Unlike epidermoid cysts, which originate from the skin, and unlike pilar cysts, which come from hair follicles, true sebaceous cysts are rare and originate from your sebaceous glands.
Sebaceous cysts can be found on your entire body (except the palms of your hands and the soles of your feet). When squeezed, the punctum (a small dome-shaped projection) will appear. Through that opening, the fluid (sebum) inside may be squeezed out.
Sebaceous cysts are usually harmless. Very few can become malignant (cancerous).
Epidermal inclusion cysts are sometimes mixed up with sebaceous cysts. Note that epidermal inclusion cysts do not involve the sebaceous gland.
What are the sebaceous glands?
Sebaceous glands are located all over your body, especially where there’s hair, although there are few on your hands and feet and zero on your palms and soles. The locations with the greatest glands per square centimeter include the ear canal, genitals, mid-back, chin and forehead. Each gland is made up of a lobe connected by ducts. Most sebaceous glands connect to hair follicles while others open on the surface of your skin. Your sebaceous glands produce a mixture of lipids called sebum. The lipids include:
- Wax esters.
- Free fatty acids.
- Cholesterol esters.
Each sebaceous gland lives for about a week and produces sebum when it disintegrates. Sebum makes up part of the oil on your skin. It has several functions:
- Sebum reduces water loss from the surface of your skin.
- Sebum causes some of your body odor.
- Sebum protects your skin from infection by bacteria and fungi.
- Sebum is colonized by a bacteria called Propionibacterium. Propionibacterium and may play a role in regulating the immune system.
Are sebaceous cysts common?
Sebaceous cysts are far less common than other types of similar cysts such as epidermoid cysts and pilar cysts.
Are sebaceous cysts painful?
Sebaceous cysts normally don’t hurt, but they can become tender, sore and red if they get infected. One sign of infection is redness and swelling around the cyst or foul-smelling drainage seeping out of the cyst. See your healthcare provider if you have such symptoms.
Are sebaceous cysts cancerous?
Sebaceous cysts are common and harmless but, rarely, a sebaceous cyst can become malignant (cancerous).
A sebaceous cyst is possibly cancerous if it has any of these characteristics:
- A sign of infection such as pain, redness or pus drainage.
- A fast rate of growth after being removed.
- A diameter that’s larger than five centimeters.
It is difficult for the layman to tell whether a lump is a cyst or something else. If it’s not a sebaceous cyst, then you might need some sort of treatment. See your healthcare provider.
What’s the difference between a cyst and a boil?
A boil is a painful collection of pus that forms in the skin because of a bacterial infection. Sometimes a sebaceous cyst can become infected, developing into a boil or skin abscess.
Who do sebaceous cysts affect?
You can get a sebaceous cyst at any age.
Are sebaceous cysts contagious?
No, sebaceous cysts are not contagious.
Are sebaceous cysts permanent?
A sebaceous cyst may go away on its own. However, without treatment, you could have it for life.
Symptoms and Causes
What causes sebaceous cysts?
Sebaceous cysts come from your sebaceous glands. Cysts can develop if the gland or its duct (the passage through which the sebum leaves for the skin) gets damaged or blocked. This usually happens as a result of some sort of trauma in the area such as a scratch, a surgical wound, or a skin condition like acne. The cysts can also form because of a misshapen or deformed duct, or genetic conditions such as basal cell nevus syndrome.
What are the symptoms of sebaceous cysts?
The main symptom of a sebaceous cyst is a small 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 if the cyst is inflamed.
Do certain foods worsen or improve a sebaceous cyst?
No known foods or drinks affect sebaceous cysts.
Is a sebaceous cyst a sign of cancer?
Sebaceous cysts are rarely harmful. However, there have been some rare cases where the cysts have become malignant. Discuss your concerns with your healthcare provider.
How long do sebaceous cysts last?
Some cysts go away on their own while others continue to grow until you get treatment. Without treatment, you may have the sebaceous cyst for the rest of your life.
Diagnosis and Tests
How are sebaceous cysts diagnosed?
Sebaceous cysts are far less common than epidermoid cysts. Although the appearance of a sebaceous cyst may be slightly yellowish, the diagnosis is officially confirmed after a pathologist examines the cyst after removal. In some cases, the healthcare provider will perform a biopsy to rule out other skin growths.
What tests are done on sebaceous cysts?
If your healthcare provider suspects that your sebaceous cyst is abnormal and possibly cancerous, he or she may order the following tests:
- An ultrasound to 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. This scan is done if your healthcare provider thinks you may need to have surgery to remove the sebaceous cyst. It will help the surgeon find the best route and identify any abnormalities.
Management and Treatment
How are sebaceous cysts treated?
If the cyst is small, not growing and not bothersome, the sebaceous cysts can be ignored, as they usually are not dangerous. If a small cyst becomes inflamed, your healthcare provider may inject it with a steroid drug to reduce swelling. A healthcare provider may drain a cyst that is large, tender, or inflamed. Larger cysts may need to be removed if they cause hair loss on the scalp, or interfere with clothing.
When your cyst is removed you’ll be given a local anesthetic to numb your skin. Your healthcare provider will make a cut and squeeze out the protein inside. If the entire cyst is removed, the cyst likely will not come back; but if part of the lining remains, the cyst will likely recur.
Your healthcare provider may use one of the following methods to get rid of your sebaceous cyst:
- Laser-aided excision. The cyst is drained when a laser makes a small hole.
- Conventional wide excision. This procedure leaves a long scar after the cyst is removed.
- Minimal excision. The cyst is removed using a smaller incision in the skin overlying the cyst.
- Punch excision. The cyst and a small margin of normal skin around it are removed using a cookie-cutter like scalpel.
Never try to burst and drain the cyst yourself. That could spread an infection and the cyst could grow back.
What medications help with sebaceous cysts?
If you think the sebaceous cyst is infected then you should see your healthcare provider right away. You might need antibiotics.
Is there a cure for a sebaceous cyst?
Your healthcare provider may be able to drain the cyst or they’ll refer you to a surgeon to remove it.
Are there complications or side effects of the treatment?
You’ll likely have a scar after your healthcare provider removes the cyst. There’s also a chance of infection, so your healthcare provider may give you an antibiotic ointment to apply after the procedure.
Should I see a specialist?
Only some healthcare providers can remove cysts. If your regular healthcare provider can’t do it then you’ll be referred to a specialist.
Are there any at-home remedies that can help with sebaceous cysts?
Help reduce inflammation by holding a warm towel against the cyst.
How can I reduce my risk of sebaceous cysts?
The best thing you can do to prevent a sebaceous cyst is to prevent traumas that may cause it. Avoid being scratched or hit. Get your acne treated by a dermatologist.
What medications can I take to reduce my risk of sebaceous cysts?
Although there are no medicines that can keep you from getting a sebaceous cyst, you can prevent a removed cyst from returning if you have surgery.
What foods should I avoid to reduce my risk of sebaceous cysts?
What you eat and drink has no effect on sebaceous cysts.
Outlook / Prognosis
What can I expect if I’ve been diagnosed with sebaceous cysts?
If you’ve been diagnosed with a sebaceous cyst, then you have the option to get treatment, or to wait and see if it goes away. If you decide on treatment, you can choose what kind you want – whether it’s draining the cyst or having it surgically removed.
How long will I have sebaceous cysts?
Your sebaceous cyst may get better on its own. If it doesn’t, you can get treatment to remove it.
Can sebaceous cysts get worse?
Sebaceous cysts can grow with time. Some get so big that they interfere with how you wear clothes. Sometimes the only option is to surgically remove them.
What is it like living with sebaceous cysts?
Living with sebaceous cysts can be difficult for some people, especially if the sebaceous cyst is in a very obvious spot like on the hand or scalp.
How do I take care of myself?
Report your symptoms to your healthcare provider. Never try to burst and drain the cyst yourself. That could 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 sebaceous cysts?
Always see your healthcare provider if you find a lump on your skin. If might be a sebaceous 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 sebaceous cysts?
- Do I have a sebaceous 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 sebaceous 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
Don’t hesitate to contact your healthcare provider about anything wrong with your skin. Even if you’re 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 sebaceous cyst, or it might be something dangerous. Rely on your healthcare provider for a clear diagnosis and correct treatment options.