Benign nasopharyngeal teratoma in an adult patient

Oral Epignathus with Maxilla Duplication: Report of a Rare Case

“…Teratomas are monstrous lesions that are composed of tissues foreign to the part in which they arise, and they are exceptionally rare tumors in the head and neck region. [1][2][3] When these tumors are located in the oral cavity and are composed of all layers of germ cells and contain fetal structures or organs, they are called epignathus (which is even rarer). Another pathological variant of epignathus is "fetus-in-fetu" occurring due to the incomplete twinning of monozygotic twins at a primitive stage of the beginning of axial development.…”

“…Oropharyngeal teratoma originates from the skull base craniofacial structures, particularly the sphenoid, palatine, and ethmoid bones 23. Histologically, it can be classified into four types:1 dermoid (mesodermal and ectodermal derivatives),2 teratoid (three germ layer derivatives),3 true teratoma (three germ layer derivatives, intermediate differentiation), and4 epignathus, in which the germ cell elements are highly differentiated and has fetal structures 4. Epignathus is extremely rare and its incidence varies between 1:35,000 and 1:200,000 live births with a female predominance (3:1) 5.…”

“…Morlino et al2 introduced the term “craniofacial teratoma syndrome” to define this phenotype as a recognizable developmental field defect of the cephalic pole. This entity comes accompanied by several degrees of craniofacial duplication, which can be subdivided into four general types:1 single mouth with duplication of the maxillary arch,2 supernumerary mouth laterally placed with rudimentary segments,3 single mouth with replication of the mandibular segments,4 and true facial duplication 2…”