Common subtypes of ovarian germ cell tumours include which?

• A. Dysgerminoma, yolk sac tumour, and immature teratoma
• B. Granulosa cell tumour
• C. Serous cystadenocarcinoma
• D. Mucinous tumour

Answer: (D)

Ovarian germ cell tumours come from primordial germ cells and are most common in younger women. The classic subtypes you’ll see include dysgerminoma, yolk sac tumour, and immature teratoma. Dysgerminoma is the female counterpart to seminoma in the testis and is the most common malignant germ cell tumour in adolescents. Yolk sac tumours secrete alpha-fetoprotein and have a characteristic histology; immature teratomas contain immature fetal-type tissues and have malignant potential. These subtypes are all germ cell–origin tumours with distinct behaviors and marker profiles, setting them apart from other ovarian tumours.

Granulosa cell tumours come from sex cord-stromal tissue, not germ cells, and serous cystadenocarcinomas and mucinous tumours are epithelial ovarian tumours, not germ cell tumours. So the subtypes that truly reflect germ cell origins are the ones listed as dysgerminoma, yolk sac tumour, and immature teratoma.