Teratoma.

Thompson L.
Ear Nose Throat J. 2005 Feb;84(2):75.
FIRST PARAGRAPH: Teratomas are neoplasms made up of tissues foreign to the site of occurrence. They contain tissue from all three embryonic germ layers (endoderm, mesoderm, and ectoderm). Other terms–choristoma, hamartoma, heterotopia, epignathus, and dermoid–refer to separate, unique entities that are not covered here.
PubMed ID: 15794539
Article Size: <1 MB