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Epidermal inclusion cysts, also called keratin or epithelial cysts, are benign lumps that develop beneath the skin. They are the most common cutaneous cysts and can be found anywhere on the body, with the face, neck, and trunk being the most common locations. Epidermal inclusion cysts are caused by a build-up of keratin due to obstruction or disruption of the skin or skin follicle. It presents as a slow-growing, painless lump, usually with a punctum in the middle that represents the blockage of keratin excretion. No treatment is usually necessary unless they cause pain, cosmetic concerns, or become infected. Surgical excision appears to be the mainstay of treatment, which prevents cyst recurrence. Here, we present the case of a 64-year-old male with a mass on his upper back. The mass was noted to be gradually enlarging, and thus excision was performed in order to prevent further growth and infection.
Epidermal inclusion cysts, otherwise known as epidermoid cysts or simply epidermal cysts, are a type of benign tumor most commonly associated with glabrous skin.1 They are most commonly found on the face, scalp, trunk or neck regions.2 Epidermal inclusion cysts are of ectodermal origin3 and are generally slow growing and appear to be surrounded by epithelial cells and composed of a keratinous mass internally.1 The incidence of epidermal inclusion cysts is twice as high in males compared to females.4 Epidermal inclusion cysts are classified as either primary or secondary; primary cysts develop from the infundibulum and secondary cysts develop following the implantation of the follicular epithelium within the dermis following trauma or formation of comedones.4 Diagnosis of epidermal inclusion cysts is typically clinical and is determined by a cyst and can have a dark central comedone.5 Treatment depends on whether or not the epidermal cyst is self-resolving; if not, then surgical intervention is required.4
The 64-year-old male presented with an epidermal cyst on his left upper back with a punctum on the surface. The cyst had been growing for several months. There were no known allergies or contraindications.
Physical examination revealed a healthy-appearing, adult male. A soft, unilateral, palpable mass was located on the patient’s left upper back. No loss of function or range of motion was reported in this case.
If an epidermal cyst is located near a nerve, vessel, bone, breast tissue, or in intracranial locations, MRI or CT imaging should be done.2 Epidermal cysts have the potential to compress nerves and cause spasms6, which is why caution should be taken when excising masses from the areas noted above.
The pathophysiology of epidermal cysts varies. The majority of epidermal cysts originate from the follicular infundibulum below the skin5. As stated in the video, epidermal cysts can return after excision if a portion of the fibrous capsule is not removed during the surgery.
If the cyst is small, uncomplicated, and can be kept clean, treatment is not necessary.5 Surgical incision before the cyst becomes infected may prove beneficial as the surgical planes may be less evident should the cyst become infected.7 Patients may, however, request the excision of cysts for aesthetic reasons. If the epidermal cyst is to be removed, surgical excision is preferred to minimize risk of recurrence of a second cyst in the future.
Minor epidermal cysts without symptoms can be left untreated. If the cyst becomes infected or inflamed, or if the patient prefers excision for cosmetic purposes, surgical excision is warranted.
No special considerations were considered for this patient.
The procedure started with cleaning the superficial region containing the cyst and injecting 2% Xylocaine to the area around the epidermal cyst while the patient lay prone. A local anesthetic will spray out of the cyst during injection if the needle crosses the cyst wall and is injected into the cyst core. A transverse, elliptical incision was made inferiorly and superiorly to the cyst, and extended roughly 2 cm laterally to the cyst. The corners of the elliptical incision are where the cyst was released from. Clamping the corners allows the surgeon to avoid puncturing the cyst wall, which will help prevent recurrence. Once the incisions have been made, and the cyst wall is identified, a scalpel can be used to dissect the tumor out. After removal, internal and external sutures were used to close off the wound. Due to the depth, internal sutures were required to stabilize the wound and prevent infection. An inverted-T suture technique with absorbable sutures was utilized with the internal suture. Non-absorbable sutures were used on the external suture.
As shown in the video, the patient was able to be discharged the same day as the procedure. There was no medical history that warranted concern for post-operative bleeding. The post-op instructions included cleaning the wound, changing the gauzes daily, and returning in one week after the surgery to remove the external sutures. Prognosis for superficial cysts such as the one in the video are excellent as they typically relieve themselves. In the rural medical setting where there are physician shortages, procedures like these can be utilized at low cost to prevent infection and improve quality of life to patients who may have to wait months to years for elective procedures.
No specialized equipment was used in this case.
Nothing to disclose.
The patient referred to in this video article has given their informed consent to be filmed and is aware that information and images will be published online.
- Wollina U, Langner D, Tchernev G, França K, Lotti T. Epidermoid cysts - a wide spectrum of clinical presentation and successful treatment by surgery: a retrospective 10-year analysis and literature review. Maced J Med Sci. 2018;6(1):28–30. doi:10.3889/oamjms.2018.027.
- Fromm LJ, Elston, DM, Zeitouni NC. Epidermal inclusion cyst. Medscape. 2018. https://emedicine.medscape.com/article/1061582-overview.
- Janarthanam J, Mahadevan S. Epidermoid cyst of submandibular region. J Oral Maxillofac Pathol. 2012;16(3):435-437. doi:10.4103/0973-029X.102511.
- Weir CB, St.Hilaire NJ. Epidermal Inclusion Cyst. StatPearls. Treasure Island (FL): StatPearls Publishing; 2020 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK532310/.
- Hoang VT, Trinh CT, Nguyen CH, Chansomphou V, Chansomphou V, Tran TTT. Overview of epidermoid cyst. Eur J Radiol Open. 2019;6:291–301. doi:10.1016/j.ejro.2019.08.003.
- Alemdar M. Epidermoid cyst causing hemifacial spasm epidermoid cyst in cerebellopontine angle presenting with hemifacial spasm. J Neurosci Rural Pract. 2012;3(3):344–346. doi:10.4103/0976-3147.102618.
- Zito PM, Scharf R. Cyst, Epidermoid (Sebaceous Cyst). StatPearls. Treasure Island (FL): StatPearls Publishing; 2020 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK499974/.
Cite this article
Grove J, Suntay MLR. Excision of epidermal inclusion cyst. J Med Insight. 2022;2022(268.16). doi:10.24296/jomi/268.16.
This is a 64-year-old male with a mass, which had been growing for a couple of months now. These are normally what we do in surgical missions. The small lumps and bumps. But we, we would want always to get it at an early, at an early time, rather than it gets bigger, and it gets infected. So this is a small mass, this is what they call an epidermal inclusion cyst. A simple cyst, which forms because of an obstruction, an obstruction here in the hair follicles. So since the gland normally secretes oils and some sweat, if it gets clogged by dirt, so the - the oils get accumulated inside, and then they become a cyst like this. So, this could normally get infected, it also could cause some pain, if it gets a little bigger. We'll be doing the surgery now, we've already prepped the patient, cleaned the area, and put a sterile dressing over it, as to avoid contamination.
I'll be injecting now 2% Xylocaine, which is a local anesthetic, which should numb out the area in a couple of seconds. So what's important when you do the incision is you plan out where you're going to incise, and that's where you'll be infiltrating the Lidocaine I normally check the location - to be able to check the anatomy if there are any structures here underneath, which are dangerous in this area, no significant blood supply would be really near the area. Nice to find out the muscles here, muscles go down this way- and also muscles this way. But I also follow the, what they call the line of Langer, which is this way, as compared to going down. So my incision would be a transverse incision from here to here, I'll probably take it this way. So I'll start injecting now. So, best to aspirate, just to check that you're not intravascular, then you start injecting slowly. And then go around it. I try to stay above- just to the skin area, you can see, it went through that small hole there, which is where it starts, there. We're going to go a little further there. If you see it come out, that means you're inside the cyst, so I just pulled it back a bit, and you can - a little lateral to the cyst. There, you can see blanching of the skin. And I'll go around it. So where I finished off the last infiltration - I just go a little more. So, there's - I don't see any Lidocaine coming out of the - of this hole, so I'm definitely - I'm not, I'm not inside the cyst. And I went already on top, I'll go down. So I aspirate again, just in case. Infiltrating a little more. I just asked him if he was okay, he's feeling okay. He should normally just feel a sting, but some patients get dizzy. So I already injected - I infiltrated above, skin level, and maybe some subcutaneous tissue. I would want to go a little deeper here. Just to be able to block the bed. One last one here. Aspirate. It should be good. I wait for a few minutes, for the anesthetic to take full effect before I start my incision. Other surgeons use a combination of Lidocaine and epinephrine, you could use that too if you want, just to minimize the bleeding. I normally use that for the face and some other areas, which are more vascular, but for this area, I think we should be okay. So it's important if you ask - you ask the patient if he does feel that the area would be, would be numbed. Okay, so I asked him if he felt - if there was still any, any pain, or if he felt a little numb already. He said he feels - it's a little numb. I told him to just tell me if he feels any pain, I could inject more anesthesia if he does need.
So, I'll start. I normally do an elliptical incision, just to cover this hole here. So I'll start down here. As I mentioned, I'll do it transverse. I made the incision underneath. And one other incision above. And you see it, you see the lighting there. So you can see the incision for this, and then we're going to close it this way. You should make it a little deeper, lower in the skin.
I normally want to get the corner first. So, I release the corner. Because if I release it in the corner, as compared to releasing it here in the middle part, you might puncture the cyst. It's important to get the whole cyst wall, or if you don't, you'd have recurrence. So if you start off here in the - on the corner, which as you can see, a while ago, in the, the cyst formation, it seems like this is already going to be a normal, normal tissue. You can grab onto the side of the cyst here, just to pull it - retraction. I'll have my assistant here - pull this back, retract here. So the basics for surgery would be to have traction, counter-traction. That allows us to be able to dissect easier. So you can see him pulling that side, I'm pulling this side, so when you make an incision, it will be easier. So I just continue dissecting around the cyst. Hopefully, I don't puncture it. So I try to stay superficial before I go a little deeper. And you can see the cyst wall here already. A little popping out. I'll go to the inferior part, lower part. More up there, please. So, I already made the incision here. I'll go a little deeper here. Again, I'd want to get the corner here, just like what I did on the other side. So I'm just cutting a bit here, until I get a little deeper. You go on top. The tissues here on the back are a little tougher, as compared to probably other areas in the body. So, you'll have to have more, more strength in the dissection there. Blade. So again, I'll try to release the corner first. Other surgeons use a Metz, Metzenbaum scissors, but I prefer using a blade all the way. So you can wipe the area, just to see normal anatomy. So it's almost out. So it's almost out. It's important to dissect slowly. And around it, you can see this is the cyst wall, see it's thin, and here's the, the tissue, part of muscle there. So just get as much tissue you need to release. Okay, and then here's the cyst wall, completely. So as you can see, you preserve, you remove everything, even the cyst capsule. It's complete. So I didn't rupture it. If you rupture it, sometimes, you may leave some part of the cyst capsule inside, which could be a cause of recurrence. So, normally, you could do without using cautery. This will normally stop, just apply pressure for a few minutes, it'll stop, or you could also use a - a cautery to stop the bleeding. So this is a hand-held cautery. Or normally this would also stop by just putting in sutures. So what I'll do now is just apply pressure there, the bleeding should stop after awhile. What's important here is I'm trying to oppose the edges, so you can see that it could be easily opposed this way.
So you could just go straight by suturing the top with a non-absorbable suture. Since this is the back, I'll use an absorbable suture inside, just to oppose it closely, and then I'll put a non-absorbable outside, just to give more strength to the wound, and the healing to be better. So this is what we call the inverted T-suture, so I lift one edge, start in the middle, come out almost close to the edge, and then go for the other edge, coming from on top, going down, coming out again in the middle. A double-knot, just to keep it closed. Normally I do around 4 or 5 knots for this type of suture. My objective is just to add strength to the tissues underneath. I'll put one more here, before I put the absorbable suture outside. And just a double-knot, a single throw underneath, I'll do one on top here. And you cut this short, this is - this will normally absorb after a few weeks to a month, months sometimes. You could either use this, to have a cleaner, cleaner wound, underneath, but normally during surgical missions, I use absorbable, it's faster, because we normally do a lot of lumps and bumps for surgical missions. Normally, some surgeons would always like doing, of course, the bigger surgeries, but I still feel that these smaller surgeries will help out a lot for the patient because if not done at an early stage like this, you normally have this grow bigger, and it'll be more difficult for the patient. So doing this routinely, offering the services of surgical mission groups. And this suture has to be removed after a week. This is a simple, interrupted stitch. Just go in in one end, out in one end.And then just two knots. And the wound has to be cleaned daily as much as possible, with normal iodine and new gauze. We try to avoid wetting the area, to allow the wound to be clean. That should be it. And we just put a normal dressing over it, just to keep the area sterile.