Developmental disorders

II./1.3.: Teratoma embryonale

Comprising 1 % of all teratomas, the teratoma embryonale contains undifferentiated tissues, mainly observed in the ovary and testis. Such tumors originate from pluripotent stem cells. Though benign by origin, these tumors show high incidence of malignant transformation. Teratoma embryonale specimens are composed of immature cartilage, bone, striated skeletal muscle, groups of trophoblast cells, pieces of yolk sac as well as cells deriving from neuroepithelium and the neural crest. The majority of cells express Oct-4, a transcription factor characteristic for Oct-4 stem cells, whereas those of non-differentiated neuroepithelium express the transcription factor Pax6.