Adult Skin Problems Slideshow Quiz: Is Ringworm Contagious? Gallery of Skin Problems and Image Collection Cyst: A closed sac or capsule, usually filled with fluid or semisolid material. From Skin Problems and Treatments Resources Could This Red Bump Be Skin Cancer?Skin Care for PsoriasisAll About Psoriatic Arthritis Featured Centers When Prostate Cancer SpreadsEssential Tips to Manage DiabetesWhat Is Cystic Fibrosis? What Causes It? Health Solutions From Our Sponsors Kept Your Wisdom Teeth? What is TAVR?