In pediatric patients, which ovarian tumor is the most common malignant germ cell tumor?

• A. Dysgerminoma
• B. Endodermal sinus tumor
• C. Choriocarcinoma
• D. Immature teratoma

Answer: (A)

In children, when an ovarian tumor is a malignant germ cell tumor, the most common type is dysgerminoma. This tumor arises from primordial germ cells and is the ovarian counterpart of seminoma, which explains its predominance in the pediatric and adolescent population. Clinically, it often presents as a unilateral pelvic mass and tends to be solid on imaging, with a tendency to be unilateral though it can be bilateral in a minority of cases. Tumor markers help with characterization: LDH can be elevated, while AFP is usually normal and β-hCG is only elevated in a subset with syncytiotrophoblastic elements. Dysgerminoma generally has a favorable prognosis and is very responsive to surgery, and often to adjuvant therapy if needed. Other malignant germ cell tumors, like yolk sac tumors, choriocarcinomas, or immature teratomas, are less common in this age group and have different marker profiles (elevated AFP for yolk sac, elevated β-hCG for choriocarcinoma).