Histogenetic analysis of ovarian germ cell tumors by DNA fingerprinting

The histogenesis of ovarian germ cell tumors (11 mature teratomas, three malignant transformations of mature teratomas, two immature teratomas, and four dysgerminomas) was investigated genetically using minisatellite DNA probes 33.15 and 33.6 for person-specific restriction fragment length polymorphism (DNA fingerprint) analysis. The DNA fingerprints of six ovarian teratomas were identical with those of mononuclear cells from each host, while some polymorphic bands observed in the host mononuclear cells were lost in the DNA fingerprints of the other five cases. The cases of malignant transformation of mature teratoma and immature teratoma showed that some polymorphic bands of DNA fingerprints from the host mononuclear cells were absent in the tumor tissues. In four cases with dysgerminomas, the DNA fingerprints of tumors were completely identical with those of the respective host mononuclear cells. The present results suggest that mature cystic teratomas of the ovary arise from germ cells arrested at various stages of meiosis, while immature teratomas are derived from postmeiotic germ cells. Malignant transformation may occur exclusively in the mature teratomas arising from postmeiotic germ cells. Dysgerminomas develop from premeiotic oogonia (primordial germ cells). Thus, DNA fingerprints are a useful and sensitive tool for identifying the pathogenesis of germ cell tumours.