Sebaceous Cyst

What it is

A sebaceous cyst is a small, closed sac that forms just beneath the skin's surface. It's filled with a thick, oily substance called sebum. These cysts develop when an oil gland or hair follicle gets blocked.

How common it is

These cysts are common and can appear anywhere on the body. While they are not part of the breast tissue itself, they can sometimes form on the skin of the breast.

What you may notice

You might feel a small, round, firm lump that can be easily moved under the skin. It is usually painless unless it becomes irritated or infected.

What can contribute

Sebaceous cysts typically form when a skin pore or hair follicle becomes blocked. Sometimes, a minor scratch or injury to the skin can also lead to one.

How it is usually checked

Your provider can usually identify a sebaceous cyst during a physical exam. If there's any question about the lump, they may use an ultrasound to get a better look. In some cases, they may suggest a small procedure to remove it and confirm what it is.

Does this change my long-term risk?

Having a sebaceous cyst on the skin of your breast does not change your long-term breast health risk.

Comfort and everyday care

• Applying a warm, moist cloth to the area may help ease any discomfort.
• It is best to avoid squeezing or trying to pop the cyst, as this can cause inflammation or infection.
• Keeping the area clean with gentle soap and water can help prevent irritation.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.