Epidermoid cysts, commonly called sebaceous cysts, are bumps that develop beneath the surface of the skin, particularly the skin of the face, neck and trunk. Sebaceous cysts typically aren't dangerous, although large cysts, especially on the face, may affect appearance or interfere with daily life. The cyst on your cheek bone will likely diminish with time and proper home care, but if it becomes very large or infected, your doctor may remove it surgically.
If the bump on your cheek bone is indeed a cyst, it is likely round in shape and yellow or white in color. You should be able to move it around easily with your fingertips. Its size may range from less than 1/4 inch to up to 2 inches in diameter. A sebaceous cyst is usually not painful, but if it becomes infected you may experience tenderness, redness or swelling. A white or yellow substance may drain from the cyst.
Sebaceous cysts are normally caused by an abnormal proliferation of skin cells that results in a blocked hair follicle. A skin injury, inflammatory skin condition or ruptured sebaceous gland may cause skin cells to multiply abnormally and block a hair follicle, creating the walls of a sebaceous cyst. The skin cells that form the wall of the cyst secrete a protein called keratin into the interior of the cyst, giving the cyst its round shape and white or yellow color. People with acne or surgical wounds are at a higher risk for developing a sebaceous cyst.
Home treatment for a sebaceous cyst involves applying warm compresses to the cyst to promote drainage. Most cysts will resolve without medical treatment. For very large cysts that are infected or of cosmetic concern, your doctor may prescribe antibiotics, inject a steroid into the cyst, or drain the cyst to reduce inflammation. Your doctor may also surgically remove the entire cyst using either a traditional excision or carbon dioxide laser which minimizes scarring.
Occasionally, infected sebaceous cysts may rupture, forming painful abscesses that require prompt treatment including antibiotics, surgery, or both. These abscessed cysts may return after surgical removal. In rare cases, sebaceous cysts can cause basal or squamous skin cancer. However, this occurs so seldom that cysts usually aren't biopsied unless they are immobile, solid, infected or have other strange characteristics.
When to See a Doctor
Most sebaceous cysts aren't harmful, but it is important to see a doctor if you suspect your skin has become infected. Signs of infection include tenderness, redness and swelling around the cyst, and a thick, yellow, sometimes foul-smelling drainage from the cyst. Make an appointment with a health professional if you have a cyst that becomes painful, grows rapidly, ruptures or keeps coming back in the same place. Any hard, painless bumps on the face should be examined by a doctor for signs of skin cancer.