Sir, On the back of my neck, left side at the hairline, a small, hard lump appeared under the skin literally over night. The lump has no coloration and is perfecty round, not irregular and pea-sized. I m in lot of pain since 6 month from now. Sir please me how it happen and how I over come from it. My age is 37 and I am male. I m from india varanasi. Waiting for your answer.