My Son Has A History Of Lump On His Tail

My son has a history of lump on his tail bone. Which was operated on an removed. But re appears. He also has lumps that appear on his butt,thy and around his groin area. When they appear it takes about a week or so to pop. A lot of liquid puss an blood come out. At the same time he also gets lumps in his arm pit area. They do not form fully and also come and go. Any help would be appreciated. Thank you