<prompt> Germ cell tumors of paediatric includes all except?Pure yolk sac tumorLeydig cell tumorChoriocarcinomaEmbryonal cell carcinoma  <response>: Ans. is b i.e., Leydig cell tumor Germ cell tumors o Germ cell tumors, as the name suggests, arise from Primordial germ cells Precursor germ cells or gametocytes, o Germ cells develops early in life. In growing fetus, germ cells migrate from their point of origin to the gondal area. o Germ cells that still have to reach the gonads are called primordial germ cells. o After reaching to gonads these become mature germ cells and the end products of germ cell cycle are the egg or sperm. o Germ cell tumors arise from primordial germ cells. o Therefore germ cells tumor may be : Gonadal In testis or ovary ii Extragonadal : - When primordial germ cells fail to reach the right location and divide at the site of arrest. Extra-gonadal germ cell tumors may occur at mediastinum most common site, retroperitonium 2nd most common site, brain, pineal gland, sacrococcygeal region. o Germ cell tumor are : Seminomadysgerminoma Embryonal carcinoma Yolksac endodermal sinus tumor Choriocarcinoma Teratoma Non-germ cell gonadal tumors o These tumors occur in adults. These may occur very rarely in children and occur predominantly in ovary. Tumors are : - i Surface epithelial tumors : - Serous tumor, mucinous tumor, Brenner tumor etc. ii Sex cord stromal tumors : - Granulosa-theca cell tumor, Seoli-Leydig cell tumor. 