I was checking my 6 week old chicks and noticed that one of the buff orphingtons has a large ping pong ball sized growth under the skin. It is on the right side of her body on the outer breast near the joint of her wing. It feels firm to the touch and there is no inflammation on the surface of the skin. The chicks were vaccinated for Marek's and are still on medicated chick feed. Wondering what I should do.... would there be any reason to isolate her? She seems perfectly healthy otherwise, is this something I should just keep an eye on? Not sure the ramifications of a tumor in a chick. Any input would be appreciated.