Sebaceous Cyst

Epidermoid cysts (sebaceous cysts)

Epidermoid (ep-ih-DUR-moid) cysts are noncancerous small bumps beneath the skin. Epidermoid cysts can appear anywhere on the skin, but are most common on the face, neck and trunk.

Slow growing and often painless, epidermoid cysts rarely cause problems or need treatment. But you may choose to have a cyst removed by a doctor if its appearance bothers you or if it’s painful, ruptured or infected.

Many people refer to epidermoid cysts as sebaceous cysts, but they’re different. True sebaceous cysts are less common. They arise from the glands that secrete oily matter that lubricates hair and skin (sebaceous glands).

Symptoms

Epidermoid cyst signs and symptoms include:

  • A small, round bump under the skin, usually on the face, trunk or neck
  • A tiny blackhead plugging the central opening of the cyst
  • A thick, yellow, foul-smelling material that sometimes drains from the cyst
  • Redness, swelling and tenderness in the area, if inflamed or infected

When to see a doctor

Most epidermoid cysts don’t cause problems or need treatment. See your doctor if you have one that:

  • Grows rapidly
  • Ruptures or becomes painful or infected
  • Occurs in a spot that’s constantly irritated
  • Bothers you for cosmetic reasons

Causes

The surface of your skin (epidermis) is made up of a thin, protective layer of cells that your body continuously sheds. Most epidermoid cysts form when these cells move deeper into your skin and multiply rather than slough off.

The epidermal cells form the walls of the cyst and then secrete the protein keratin into the interior. The keratin is the thick, yellow substance that sometimes drains from the cyst. This abnormal growth of cells may be due to a damaged hair follicle or oil gland in your skin.

Many people refer to epidermoid cysts as sebaceous cysts, but they’re different. True sebaceous cysts are less common. They arise from the glands that secrete oily matter that lubricates hair and skin (sebaceous glands).

Tests and Diagnosis

Doctors can usually make a diagnosis by looking at the cyst. Your doctor may also scrape off skin cells and examine them under a microscope or take a skin sample (biopsy) for detailed analysis in the laboratory.

Epidermoid cysts look like sebaceous cysts, but they’re different. True epidermoid cysts result from damage to hair follicles or the outer layer of skin (epidermis).

Treatment

You can usually leave a cyst alone if it doesn’t cause discomfort or cosmetic problems. If you seek treatment, talk with your doctor about these options:

  • Injection. This treatment involves injecting the cyst with a medicine that reduces swelling and inflammation.
  • Incision and drainage. With this method, your doctor makes a small cut in the cyst and gently squeezes out the contents. This is a fairly quick and easy method, but cysts often recur after this treatment.
  • Minor surgery. Your doctor can remove the entire cyst. You may need to return to the doctor’s office to have stitches removed. Minor surgery is safe and effective and usually prevents cysts from recurring. If your cyst is inflamed, your doctor may delay the surgery.
  • Lasers. This method involves using a carbon dioxide laser to vaporize the cyst. It results in minimal scarring.

Source: http://www.mayoclinic.org