What Is a Sebaceous Cyst?

You notice it almost by accident — a small, round lump under the skin that wasn't there, or at least wasn't noticeable, a few months ago. It doesn't really hurt. It just sits there. If that sounds familiar, you're in common company: the short video above, "Sebaceous Cyst Removal," runs for about 48 seconds and describes sebaceous cysts as common, noncancerous cysts of the skin. Here's what to expect if one of these is what you've found.

First, what you're actually feeling

A cyst, as the video explains, is an abnormal pocket in the body that may contain liquid or semiliquid material. A sebaceous cyst is that kind of pocket in the skin. The video notes that they're mostly found on the face, neck, or torso, and that they grow slowly and are not life-threatening. That slow pace is worth knowing upfront: a lump that has crept up gradually over months fits this picture very differently from something that appears overnight, and your clinician will want to hear how long it's been there and whether it's changed.

What the appointment usually looks like

You might expect scans and tests. Often, there aren't any at first. The video explains that doctors usually diagnose a cyst with only a physical examination and a medical history — looking at it, feeling it, and asking you about it. In some cases, though, a cyst will be examined more thoroughly for signs of cancer. So if you're sent for a closer look, that doesn't automatically mean something serious has been found; it means that particular cyst needs more than a surface check before anyone settles on a name for it.

When a quiet lump stops being quiet

Most of the time, expect very little drama. The companion video on this site about an infected sebaceous cyst puts it plainly: a sebaceous cyst usually grows very slowly and doesn't cause pain. But it also explains what can change that — a cyst can become inflamed or infected, with the skin over it becoming red, tender, and sore. Location can play a part, too: a cyst on a spot that's constantly irritated, such as one on your neck that rubs against your collar, is more likely to bother you. A lump that turns red, tender, or sore is no longer a "watch it and see" lump — that's the point at which to get it seen promptly.

Is it the same as a lipoma?

Not quite, and it's a fair question, because both turn up as soft lumps under the skin. They're different kinds of growth, which is why an in-person examination matters rather than a guess based on how a lump feels through your fingers. If you're comparing possibilities, our guide to what a lipoma is covers that other common lump in detail. And what about removal? The anchor video is itself a brief removal recording, so you can see the setting for yourself — but whether a particular cyst should be removed, drained, or simply left alone and monitored is a decision for the clinician who has examined it, not something to settle from a video.

Frequently Asked Questions

Are sebaceous cysts cancerous?
The anchor video describes them as common noncancerous cysts of the skin that are not life-threatening. It also notes that in some cases a cyst is examined more thoroughly for signs of cancer, which is one reason any new lump deserves an in-person check rather than an assumption.

Where do sebaceous cysts usually appear?
Mostly on the face, neck, or torso, according to the anchor video. They grow slowly, so many people notice them only once they've become large enough to feel or see.

How is a sebaceous cyst diagnosed?
Usually with a physical examination and a medical history alone, the video explains. A closer examination is used in some cases, particularly where the cyst needs to be checked more thoroughly.

When should I get a skin lump seen promptly?
If it becomes inflamed or infected — red, tender, or sore, as the infected-cyst video describes — or if it's on a spot that's constantly irritated and keeps bothering you. A lump that is changing, rather than sitting quietly, should be assessed in person.

MedicalVideos.com has published trusted medical videos since 2007. The site was founded by Dr. Mohamed Ibrahim, MD, PhD — physician-scientist.

Educational only — this article is general information about sebaceous cysts, not medical advice and not a diagnosis. Any new, changing, red, tender, or sore lump under the skin should be assessed in person.