Chet, My Regal Angel had a little of the Lymphocystis growth on his fin. It is viral and you can't really treat it. I believe my cleaner shrimp was able to pluck it off. Good quality food and water will eventually allow the fish to fight it off. Also make sure it isn't getting picked on by other fish. Stress weakens a fish and thus its immune system and makes it harder to fight off infections.