A tumor consisting of displaced ectodermal structures along the lines of embryonic fusion, the wall being formed of epithelium-lined connective tissue, including skin appendages, and containing keratin, sebum, and hair. (Stedman, 25th ed). The disease is Experimental Factor Ontology id EFO_1000894 (dermoid cyst). Also known as: Dermoid Cyst, Dermoid choristoma, Dermoid tumour, Mature cystic teratoma, cystic dermoid choristoma, teratoma, benign, teratoma, benign (morphologic abnormality).