My dad (68 yrs old) just recently went through radiation for tounge cancer. He finished his tx about a month ago, which was after he had the very small mass removed. Last night he noticed a small, pea sized, non-painful, not raised lump just below the skin in his right armpit. Also the same side he had the radiation on. It doesn't feel deep, just below the skin. No pain at all, he only noticied it when he was washing up. He had a negative pet scan just before his operation. Please tell me this isn't anything to worry about!!! It seems like we just finished going through this horrific diagnosis and I feel we are starting over at day one.