So, you think you have a sebaceous cyst — and you're hoping to get rid of it? Here's what you need to know.
Signs You're Dealing With A Skin Cyst
A cyst is a closed sac (sometimes referred to as a capsule) filled with a liquid or semi-solid substance. Cysts can form anywhere in the body, including the ovaries, kidneys, and even the bones. 
If you're dealing with a cyst under the skin, or even several cysts, you may notice:
- A movable lump under the skin. Cutaneous cysts are most likely to affect the face, neck, scalp, torso, and arms. Sebaceous cysts on the scrotum are also fairly common.
- The lump itself is usually not painful, though the skin around it may be sore.
- Some redness and swelling may be present around the lump.
- The cyst usually grows over time, but very slowly. Unlike boils, which typically resolve spontaneously within a few weeks without boil treatment, cysts can stick around for a very long time and become very large.
- Should the cyst rupture, a foul-smelling liquid or semi-solid ("gooey substance") will drain out. 
What's A Sebaceous Cyst?
Before you see a doctor, you might be quite able to tentatively self-diagnose yourself with "a cyst of the skin", but what kind of cyst do you have? Some people refer to any cyst of the skin as a sebaceous cyst, but it isn't quite that simple.
Dr Sasa Milosevic, SteadyHealth's own "in-house physician", points out that "the terminology is tricky, even in the scientific literature". He adds: "When people say 'sebaceous cyst', they usually think of pilar cysts arising from hair follicles. Real sebaceous cysts, which appear due to sebaceous-gland abnormalities and an accumulation of sebum, are rare."
The term sebaceous cyst is very often, but erroneously, used to refer to:
- Pilar cysts are fairly common — they affect between five and 10 percent of the population, and nine out of 10 cases are found on the scalp, with many of the remaining cases affecting the neck region. That makes sense, since they arise from the cells found at the root of hairs. Pilar cysts are nearly always non-cancerous. 
- Epidermoid cysts, also frequently called epidermal cysts, are lined with cells resembling those found in the epidermis, the outer layer of the skin . Most skin cysts that aren't on the scalp will fall into this category. These cysts grow slowly and can appear anywhere on the skin, with seven percent developing in the head and neck region. 
Both these kinds of cysts are more common than true sebaceous cysts. Despite arguments over the correct terminology to use, we'll use the term "sebaceous cyst" to refer to any of these three kinds of cysts in the rest of this piece, for simplicity's sake.
The good news? Unless a cyst is examined under a microscope, you won't know what kind of cyst it is — and you don't need to know in order to have your cyst removed. 
Sebaceous Cyst Removal: What To Expect
It's always good to get your (suspected) cyst checked out by a doctor, preferably a dermatologist. Unless it is large, unsightly, or your doctor is worried about the cyst being malignant, you will not necessarily have to have it removed. Many people with sebaceous cysts will want to have their cysts removed, however.
If you are ready to have your cyst removed, it's important to note that simply draining the fluid or semi-liquid substance from the cyst will temporarily create the appearance that it's gone. Looks can be deceiving, however, as the sac is still present and will very likely fill up again over time. Simply having a cyst drained is, therefore, a bad idea. Traditional, open, surgery is not necessary either. Minimally-invasive surgical techniques allow your sebaceous cyst, pilar cyst, or epidermal cyst to be removed under local anesthesia on an outpatient basis.
You can expect either of the following techniques to be used for sebaceous cyst removal:
- An incision is made into the skin that covers the cyst, just big enough to allow your dermatologist access to the cyst. Depending on how large the cyst is, the entire sac may be removed without puncturing it, or your dermatologist will first drain the cyst and then remove the sac. This is done to prevent the need to make a larger incision. All remnants of cyst tissues will be excised at the same time, and you will then receive sutures. After sebaceous cyst removal using this technique, your risk of recurrence is very low. 
- Your dermatologist may also use the punch technique. A small, round blade is used to make a hole in the skin to access the cyst. The cyst is then drained and its sac, along with other tissues related to the cyst, removed. This technique leaves very minimal scarring and comes with a recurrence rate of around 10 percent. 
Following sebaceous cyst removal, your dermatologist will give you some care instructions to promote healing. These will include the use of an antibiotic ointment, refraining from showering for 36 hours, monitoring the site for oozing and bleeding, and returning to your doctor if you notice a recurrence of the cyst. You may also need to have your stitches removed. 
Should your cyst rupture spontaneously before you have had the chance to have it removed, you will be prescribed antibiotics, followed by complete cyst removal.