“Teratoma” is derived from the Greek term meaning “monstrous tumor,” demonstrative of the often dramatic appearance of this lesion. Teratomas are believed to arise secondary to developmental errors in totipotential germ cells and are composed of elements from all 3 germ layers—the endoderm, mesoderm, and ectoderm.1 The types and distribution of tissues result in a heterogeneous appearance, both within and between tumors. The composite tissues are often foreign to the region of the body in which the lesion is located.2