DNA Ploidy: Mature post-pubertal teratoma has aneuploid DNA content (usually hypotriploid). The i(12p) marker chromosome is present in the tumor as well as in the fibrous stroma. Prepubertal-type teratomas have normal karyotype and lack 12p amplification. This image from a mixed germ cell tumor shows teratoma on the left consisting of a nodule of hyaline cartilage. The cytologic atypia approaches that seen in low-grade chondrosarcomas. On this right is a focus of embryonal carcinoma.