It is not unusual to find a lump on your body. When one is found, it is easy to worry that you may have cancer. Cancer is always something to think of. However, there are many common lumps that are not cancer; indeed, most are not. One of the most common non-cancerous lumps is the sebaceous cyst. These are extremely common. I see them every few days in my practice. When I do, I am happy to tell my patients that the lump may be bothersome, but it really isn’t anything to worry about.
What does a sebaceous cyst look like? Usually, like a small volcano with the top smoothed off. It is firm and attached to the skin — it doesn’t move around. It can be smaller than a green pea or up to 2 or more inches across. It will often have a tiny dark pore on the top of it. If you squeeze such a cyst, white material that looks like ricotta cheese and smells much worse may come from the black pore on top. Sebaceous cysts start small and gradually grow larger, often over a period of years. Sometimes they become red, infected and painful. They generally have no increased risk of cancer when compared with normal skin.
What is a sebaceous cyst? It is common — literally millions of Americans have them. It is a cavity associated with the outer layer of the skin that fills with foul-smelling substances made of skin flakes and oils. Sebaceous cysts frequently cause no problems other than being somewhat unsightly. However, they may become infected. This can occur when bacteria travel through the pore in the skin and infect the white material inside the cyst. When this happens, the cyst and the skin around it will become painful, red and hot.
What should you do if you think you have a sebaceous cyst? First, don’t squeeze or poke it with a needle. Many of the bad infections I see associated with sebaceous cysts occur when people introduce bacteria into the cyst by squeezing or poking it. Nothing good ever comes from trying to get rid of a sebaceous cyst on your own. You should, as with all lumps and masses on the body, go to your doctor. Your doctor can quickly verify whether what you have is a sebaceous cyst and basically nothing to worry about or something more serious.
What will your doctor recommend? Often, nothing. As I mentioned, sebaceous cysts generally have no increased risk of cancer as compared with other skin on the body. If they are painful or unsightly, your physician may elect to remove the cyst or send you to a surgeon to have it done. If the cyst is infected, it may be treated with antibiotics or an incision may be made in it to allow the infection to drain out. When the cyst is hot, red and infected, it can’t be removed with closure of the skin where an incision was made to drain it. The infection has to drain out and the area allowed healing before the cyst can be completely removed at a later date. To remove the cyst so it won’t come back, the physician will need to completely remove the cyst sack and the pore on the skin. If part of the cyst sack or the pore is left, it will be likely to cause more problems. Sometimes, larger or more complicated sebaceous cysts are addressed by surgeons.
In summary, if you have a smooth lump on your skin with a tiny dark pore in the middle that has been there a long time and gradually grows larger, go to your physician and have them verify what it is. It very likely a sebaceous cyst and is unlikely to cause you any serious problems. It will require a minor surgery for removal if removal is suggested or desired. Cysts can become infected and require surgical incision and drainage or antibiotics with complete removal at a later date. Cysts should never be squeezed of poked, as this will make the situation worse.
Until next time, good health!
Jeffrey A. Larsen MD is a board certified general surgeon who practices in The Specialty Clinic at The Providence Medical Center in Kodiak.