Congenital oropharyngeal teratoma in a neonatal goat and brief review of extragonadal teratomas in animals.

Teratomas originate from pluripotent germ cells and differentiate into the 3 germ cell layers: endoderm, mesoderm, and ectoderm. Hence, these tumors arise most often in the gonads. Extragonadal teratomas are rare in veterinary medicine. Congenital oropharyngeal teratoma, also known as epignathus, is a neoplasm that has been reported in humans and a few veterinary species. We describe the clinical, gross, cytologic, and histopathologic features of an oropharyngeal teratoma in a neonatal Boer × Nigerian Dwarf goat that died within 4 h of birth, and briefly review extragonadal teratomas in veterinary species.