Sebaceous Cyst: Symptoms, Causes & Treatment

A sebaceous cyst (more accurately in many cases called an epidermoid cyst) is a benign (non-cancerous) lump that forms under the skin's surface, usually in the form of a closed sac filled with a semi-solid (keratinous or oily) substance with a characteristic odor sometimes. These cysts often arise from blockage of gland ducts or from skin cells that grow inward and trap their secretions. They are very common and appear in multiple places, most often the face, neck, chest, back, and scalp.

A sebaceous cyst appears as a round, soft-textured lump under the skin that moves slightly when touched, grows slowly over months or years, and is often painless. A small dot (opening) in the center of the cyst on the skin's surface may sometimes be noticed. Most of these cysts cause no problem other than appearance or the feeling of a lump. But they may become inflamed or infected, becoming red, swollen, painful, and warm, and may discharge a substance when pressed. It is very important not to attempt to squeeze or open the cyst with fingers or tools at home, because this may push the contents deeper and cause infection and inflammation.

A sebaceous cyst is a benign condition and not dangerous, and does not usually turn into cancer. Many small, painless cysts need no treatment and can be left and only monitored. But if the cyst is large, in a bothersome location, continuously growing, or recurrently inflamed, removal may be advised. Treatment depends on the situation: in case of acute inflammation or infection it may need drainage and antibiotics first to calm the inflammation. Final removal is by a simple surgical procedure that excises the cyst with its entire wall (this is important to prevent recurrence, as merely draining the contents without removing the wall makes it recur). Seeing a doctor to evaluate any new or changing skin lump to confirm its nature and choose appropriate management is advised.

• A round, soft lump under the skin that grows slowly.
• Often painless and moves slightly when touched.
• Sometimes a dot (opening) in the center of the cyst.
• When inflamed: redness, swelling, pain, warmth, and discharge of a substance.

• Blockage of gland ducts or skin cells growing inward and trapping their secretions.
• Sometimes after a skin injury.
• Common on the face, neck, chest, back, and scalp.

• Diagnosis is often clinical from the lump's shape and location.
• Sometimes imaging or a biopsy when uncertain of the lump's nature.
• Evaluating any new or changing lump to confirm it is benign.

Monitoring

• Small painless cysts may need no treatment, only monitoring.

When inflamed or infected

• Drainage and antibiotics first to calm the inflammation.

Final removal

• A simple surgical procedure excising the cyst with its entire wall (important to prevent recurrence).

Do not attempt to squeeze or open the cyst at home. This content is educational and does not replace medical advice.

• Inflammation or infection (redness, swelling, and pain).
• Formation of an abscess.
• Recurrence of the cyst if its contents are removed without its wall.

• Not squeezing cysts or trying to open them to avoid infection.
• Skin hygiene and wound care.
• Seeing a doctor to evaluate any new or changing lump.