Epidermoid Sebaceous Cyst as Lump Under Arm Pit

Q: I have had a surgery for the excision of a sebaceous cyst in my armpit almost an year ago. Now I can see two small white colored spots on the wound which is still red. Especially on sunny days and hot weather and during exercises, I experience a severe pain and numbness around the wound and in my whole hand. A white colored thick liquid comes out from the wound. Is this a normal situation after one year from the surgery? Please advice me.
– By Upeka, female 26 years.


Symptoms like pain, redness and  discharge are suggestive of an infection in the underarm area. White colored discharge is likely to be keratin.

You will need to treat this infection first. An antibiotic course is required. Also, keep the arm pit area clean and dry. Also there is a need to investigate what this lesion is.
There are at least three possibilities for this infection-
  • The surgical excision of the sebaceous cyst was not complete. So it has recurred (came again) and got infected.
  • Some other sebaceous or sweat gland has got infected in that area. The condition is commonly called Hidradenitis Suppurativa.
  • The scar tissue of the surgical procedure got infected. This area is very moist and full of skin bacteria, making it prone to infections.
Let us consider the first possibility. Recurrence of the cyst after excision is not uncommon.

What Are Sebaceous Cysts ?

Our skin has oil glands in it which produce a secretion called sebum. It is an oily stuff required to keep the skin soft and prevent dryness.
Sometimes the drainage duct of this gland gets blocked. Slowly a cystic swelling results. This swelling is referred to as the epidermal sebaceous cyst. So sebaceous cyst is a lump under the skin. It is a closed sac containing a cheesy / pasty material called keratin.

Surgical Excision of Epidermoid Cyst

This is done to prevent complications caused by epidermoid cyst. Surgical excision requires complete evacuation of the contents of the cyst with complete cyst wall removal.
Like any procedure, this procedure also has many pitfalls. To list a few:
  • The cyst wall does not come out completely of the small incision. It may break and a part of it may be left behind. In such cases there are chances for the cyst to recur.
  • Some portion of the solid or semisolid content may not be expressed out. This mass solidifies and may even press against some nerve. Pressure by this lump over the nerve can give severe pain in the shoulder and whole hand.
  • After removal of a large cyst, the space emptied can sometimes get filled with infectious material or blood clots. This lump can get infected later on. Such masses can also press against the nerves of the arm and cause pain in the hand.
Second possibility is that its a new cyst troubling you.
Third possibility is that the scar tissue of the surgical procedure you had, got infected. Scar tissues need a lot of care to heal. The area needs to be kept clean and dry. This region is full of skin bacteria and moisture aids in their growth. Even a little negligence in personal care can give an opportunity to the bacteria to grow.

Self-help Measures

You may visit your doctor for an exact diagnosis of your armpit lesion. Meanwhile, take the following precautions:
  • Do not squeeze or scratch the under arm area.
  • Keep the arm pit area clean and dry.
  • Avoiding excessive sun exposure and use oil-free skin care products.
  • Tetracycline or erythromycin ointment can be applied thrice a day to the affected area.
Take Care,
Buddy M.D.

Medical Advice (Q&As) on “Epidermoid Sebaceous Cyst as Lump Under Arm Pit

  1. L Cooper

    I went to have a cyst removed in November of 2011 on my cheek. Instead of taking the cyst out, the plastic surgeon did tissue repair and put stitches on it. It opened back up within a week of the stitches being removed. The doctor kept telling me it was fine just to leave it alone and it will heal; to say the least it would close and reopen all the time.

    I went to another plastic surgeon and was in surgery 2 1/2 hours because it spread, wrapped around and twisted the muscles in my face. Now I have a 4 inch scar going down the front of my face.

    1. Buddy M.D. Post author

      Looks like that you had an infected lesion on your face, that gradually involved the deeper facial tissues.

      Since you already had a surgery for that wound, leaving a scar. So your best option is to go for another plastic surgery for scar removal later.

  2. Tiffany

    I have had a small pea size lump in my armpit for about 3 years. I woke up 3 days ago. Out of nowhere it was hurting and was the size of a walnut. The next day it had a pin size hole, and a green thick awful smelling fluid was coming out.

    So I went to the ER. They drained it an they had to squeeze really hard. They said it was really thick. They got most of it out and they left it open and packed it.

    They said I still needed to see a surgeon to have the lump removed. What could this lump be? Can it be cancerous? Why did I get this? I’m also on a skin antibiotic pill.

  3. Justme

    I am sitting in a waiting room of a surgical specialist at this moment. I’m getting a cyst removed that’s in the dead center of my armpit.

    After reading this, I’m scared and want to walk out. It’s a pretty big size lump. If I try to wrap my fingers around it, like I’m going to pull it out, it’s about as round as a big grape and about 1/4 inch deep in my skin.

    I’m scared that’s going to be a huge hole when they take it out. Now I’m freaked out that it will come back. I have an appointment in two weeks to come back because I have another one that’s much smaller but it’s located right at dead center on the back of my head on the hair line on my neck.

    1. Buddy M.D. Post author

      If your doctor wants to operate out this cyst, probably it is essential to do so. Sebaceous cysts at places like underarms are always vulnerable to complications like getting ruptured or infected. So they need to be removed.

      If the excision is done properly, that is, the whole cyst is removed out cleanly along with its outer covering, there are minimal chances of any recurrence or any other trouble.

      Post operative care is definitely required. You may follow the care written on your discharge paper. Hopefully, all will be well.

  4. Justme

    If you are saying that my nerves may get affected and my arm or hand might go numb or in pain, what will happen if the one on the back of my neck gets taken and that causes nerve damage there?

    1. Buddy M.D. Post author

      Well, these cysts are not very deeply situated. So their removal is a superficial procedure.

      Nerves and vessels at the back of our neck are deep and well protected. So, they are safe as far as the procedure is concerned.

      However, it is always imperative to take care of the post surgical wound. Make sure that it does not get infected. Infections are quick to spread and may involve deeper structures too. You will get all guidelines to take care of your wound in your discharge summary. Just follow them sincerely.

  5. Sheila

    I presented to the doctor with what I perceived as a lump under my arm in 1997. The MD detected traces of blood, assuming it was from shaving, said it wasn’t a lump and sent me home. The next morning, I awoke to am armpit full of pus, so I went back. He then diagnosed a cyst, cut it open, drained it, and I came back every day for about 2 weeks to have it packed to heal from the inside out. I have had no problems until now. A couple of months ago, I detected a problem with the same armpit. If I pressed on the hard knot, it would ooze a thick creamy fluid. I went to the doctor (a different one from the first) and he gave me clindamycin and because it had no odor, he said it was just an infected hair follicle. The antibiotic helped for a while, but it never went away. Now, not only is the hard and painful knot large, it is affecting what I believe to be my lymph nodes. It seems that the tubes that connect to a couple of lymph nodes extending down my arm are hard and my muscle in the upper (underside) of my arm is sore, too. I think whatever it is is spreading. Should I see a different doctor since this one really didn’t didn’t take it seriously? The nurse even had the tray set up to excise it, but he didn’t do anything except give an antibiotic. I really thought it was a cyst again, but with it expanding, I don’t know anymore.

    1. Buddy M.D. Post author

      It is very likely to be a cyst again. Recurrences of armpit cyst is very common.

      Since the cyst appears to be infected (you feel some soreness in your arm), you may take the antibiotic for now.

      It would be better to go to a surgeon and let him know the full history of your armpit lump. If it is a cyst again, a complete excision (along with the cyst capsule) is required to prevent further recurrences.

  6. Fatima

    So yeah, I ask I have the cyst under my armpit and I guess it is a double cyst. I really want to take it out, but after listening to my uncle who claims that after cleaning it they pull it out with the instruments, which is very painful, so I am kind of worried. Specially as everyone here is claiming that it will reoccur.

    1. Buddy M.D. Post author

      You need to talk to your surgeon, who is going to operate this. Only he can tell you the real picture.

      See, pain is not there if proper and adequate anesthesia is given before excision. As for recurrence of the cyst, this is very common, because a part of the cyst wall is usually left behind, which may give rise to the whole cyst again.

      If the operating surgeon is careful and removes the whole cyst capsule while excising out the cyst, it does not come back again.

  7. Prabhath

    I had a infected sebaceous cyst in my arm pit. I went to a doctor 14 days back. He drained the cyst, and did debridement. I had a 3 inch wound. It started to heal but it did not close completely. Now the wound is 1 inch, I could see a small yellow spot in outer layer of wound. Please suggest what it might be.

    1. Buddy M.D. Post author

      The yellow spot suggests that it’s still not healed.

      Let us know if you have any pain there, any discharge (leaking fluid) from there.

  8. April

    Cyst in armpit. Been there for about two years. Saw surgeon and he said come back if it begins to hurt. It’s sore occasionally but out of nowhere it hurts and two Of my fingers are numb. Suggestions on how to decrease size where it’s not pushing on nerves until I can g t to the doctor?

    1. Buddy M.D. Post author

      This one is very likely to be a sebaceous cyst. Most leave it as such unless it gives symptoms like pain or grows in size. In such cases, a surgical resection in recommended.


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