 [ Symptoms ] what is this small round solid slightly red bump between upper arm and breast that is not moveable  there is only 1 bump and i have had it for almost a month it is on the skin not underneath it i am a 24 year old female i have a dermatology appointment on the 21st but i am a bit anxious about it and wondered if there were ideas about it [ Disease ] the good news is this bump is on the skin usually lumps on the skin are not serious in other words not like a breast cancer which usually resides deeper in the tissue several things could cause a bump like you describe it could be a boil for example if so the good news is it can be drained treated and probably will not return other than that i would not want to speculate you have done the right thing by scheduling a medical appointment try not to feel too anxious soon you will know exactly what this thing is and then you can move forward with a treatment plan feel better soon