Among ovarian germ cell tumours, which is a recognized subtype?

• A. Dysgerminoma
• B. Yolk sac tumour
• C. Immature teratoma
• D. Granulosa cell tumour

Answer: (C)

Understanding the variety of ovarian tumours starts with germ cell tumours, which arise from the cells that would become eggs. Within this group, teratomas are one category and can be mature (usually benign) or immature (malignant). Immature teratoma is a recognized histologic subtype of teratoma, meaning it’s a distinct form within the teratoma family of germ cell tumours. Dysgerminoma and yolk sac tumour are also germ cell tumours, but they are separate histologic types rather than subtypes of teratoma. Granulosa cell tumour, on the other hand, comes from sex cord–stromal tissue, not germ cells. So the option that fits as a germ cell tumour subtype is immature teratoma; the others are different germ cell tumour types or non–germ cell tumours.