Sebaceous Cyst

What is it?

Also known as epidermoid cysts, they are small bumps that develop just beneath the skin on your face, neck, trunk and sometimes your genital area. They are slow-growing and often painless. Most sebaceous cysts don’t cause problems or need treatment. But if they’re a cosmetic concern or they rupture or become infected, they’re usually surgically removed. Sebaceous cysts are almost always noncancerous, but in rare cases, they can give rise to skin cancers.

What are the causes of sebaceous cysts?

The surface of your skin is made up of an extremely thin, protective layer of cells (epidermis) that your body continuously sheds. Most sebaceous cysts form when these surface cells, instead of exfoliating normally, move deeper into your skin and multiply. Most often, this occurs in areas where there are small hair follicles and larger oil glands (sebaceous glands), such as your face, neck, upper back and groin.

The epidermal cells, or the lining cells of the hair follicle, form the walls of the cyst and then secrete the protein keratin into the interior. The keratin is the thick yellow cheesy like substance that sometimes drains from the cyst.

Several factors can lead to this abnormal proliferation of cells, including:

  • Damage to a hair follicle. Each hair grows from a follicle, a small pocket of modified skin in the dermis, the layer of skin just below the epidermis. Follicles damaged by injuries, such as abrasions or surgical wounds, can become blocked by surface cells.
  • A ruptured sebaceous gland. Located just above the hair follicles, sebaceous glands produce sebum, the oil that lubricates your skin and coats each hair shaft. These glands are easily ruptured by inflammatory skin conditions, especially acne, making them a likely site for sebaceous cysts.
  • Developmental defect. Sebaceous cysts can begin in a developing fetus when stem cells intended to form skin, hair or nails become trapped in cells forming other tissues.
  • Heredity. Sebaceous cysts can develop in people with Gardner’s syndrome, a rare genetic disorder that causes growths in the colon, or basal cell nevus syndrome, an inherited disease that leads to several serious defects.

How can it be prevented?

In most cases there are no preventive methods to avoid sebaceous cysts. They generally occur past puberty, in those who suffer from acne or have experienced traumatic skin injury. Men are also more susceptible to sebaceous cysts. One avoidable cause is over exposure to the sun, always wearing SPF 30 or higher when exposed to the UV rays of the sun.

What are the treatments?

Sebaceous cysts, to the trained eye, are usually easily diagnosed by their appearance. In some cases, a biopsy may be necessary to rule out other conditions with a similar appearance. Sebaceous cysts most often disappear on their own and are not dangerous. However, in some cases they may become inflamed and tender. Sometimes sebaceous cysts grow large enough that they may interfere with your everyday life. When this happens, surgical removal may be necessary, and this procedure can be done at our center. Small inflamed cysts can often be treated with an injection of steroid medications or with antibiotics.