Paper II
Question
Germ cell tumours of Ovary
Answer
Germ cell tumours of the ovary arise from primordial germ cells and constitute the second most common category of ovarian tumours, most common in young women/adolescents:
- Dysgerminoma — most common malignant germ cell tumour; female counterpart of seminoma; sheets of clear cells with central round nuclei and prominent nucleoli, lymphocytic stroma; PLAP/OCT3/4/CD117 positive; highly radio- and chemosensitive with excellent prognosis.
- Yolk sac (endodermal sinus) tumour — most common malignant germ cell tumour in children; characteristic Schiller-Duval bodies (glomerulus-like structures); secretes AFP.
- Immature teratoma — malignant, composed of immature (embryonic-like) tissue from all three germ layers, most often immature neuroepithelium; graded by amount of immature neural tissue.
- Mature cystic teratoma (dermoid cyst) — benign, most common ovarian germ cell tumour overall; contains well-differentiated tissue from all three germ layers (skin, hair, teeth, sebaceous material); may show malignant transformation (rare) or a struma ovarii variant (functioning thyroid tissue).
- Embryonal carcinoma — highly malignant, primitive, poorly differentiated cells; may secrete AFP and/or hCG.
- Choriocarcinoma (non-gestational) — rare, highly malignant, secretes very high hCG.
- Mixed germ cell tumour — combination of the above elements.
Serum tumour markers (AFP, hCG, LDH) are essential for diagnosis, monitoring treatment response, and surveillance.