My husband has had an enlarged lymph node on the right side of his groin for over a year. One doctor treated it with steroids, another one recently gave him two injections at the site with cortisone, this weekend the one on the left side grew to four times the enlarged one and ruptured causing him to vomit violently for hours and rushed to the hospital for emergency surgery where they removed both lymph nodes? What would cause this? He does physical labor and lifts heavy things, all his blood test came back good and otherwise he is in good health. He is 62 years old..