Nogales FF, et al. - Researchers carried out this trial in order to report a series of 11 ovarian and one endometrial neoplasm in elderly patients with mixed clear cell tumour and germ cell tumour (GCT) components. Additionally, they compared their immunohistochemical and intended to illustrate a putative stem cell population. A significant immunophenotypic overlap was reported between the two components in these mixed neoplasms. A panel of markers was recommended for facilitating the distinction. It was hypothesized that OCT4-expressing somatic cancer cells differentiated into GCT and represent spontaneously induced pluripotent stem cells, possibly conditioned by aging-related epigenetic factors. Such neoplasms exhibited features of pre pubertal type GCT, displaying a paucity of 12p gain, preponderance of yolk sac tumour (YST) and coexistence with immature neuroectoderm. Undifferentiated stem cell areas with embryoid bodies could also exist, of the type seen in post pubertal testicular GCT but lacking a complete embryonal carcinoma immunophenotype.