I have this lump under my armpit and i get them all the time usually they go away but i have this one that is the size of a dime and when u push on it with ur finger its hallow on the inside but hard around it and it hurts it feels like there is a needle poking me i was able to put a slit in it and a bunch of puss came out of it but its so painful and i dont have medical to go find out what it is... i didnt start getting these till i got pregnant four years ago and have had them every since i also get them on my inner thigh sometimes to what are these the one under my arm has been there for awhile and has not gone away