I need to know what would be considered a dangerous lump under the arm pit. I have a lump in my arm pit that is not on the skin, there is no redness, there is just swelling like a lump. I also have mild pain in the area under the arm, running along the rib cage all the way to the center of the chest area that is seemed to be in the tissue. Pressing on it makes it ache and sort of send an ill feeling to me for a little while. It runs all the way to my chest, but never crosses over, and is all on the left side of my body. My left tonsil is a little swollen, my left armpit has a lump and my left breast line area aches. My docs told me off and on for months that I had a viral infection and there was nothing they could do, just sit it out and let me body heal. It's been months and now this is happening. I'm naturally fearing the worst.... but what else could be going on, and what is considered a dangerous lump? Any docs or nurses that can help please! Thank you.