Thyroid Carcinoma Arising From Struma Ovarii at Adolescence: A Challenging Case With Favorable Outcome

Malignant struma ovarii (MSO) is a rare and aggressive ovarian tumor that mostly affects adults but can occur in adolescents. Prompt recognition, accurate diagnosis, and multidisciplinary management are essential for favorable outcomes. Herein, we report the youngest case of an 11-year-old girl with a large MSO. First, conventional imaging revealed a large left ovarian mass, leading to a left oophorectomy. Subsequently, histopathological examination confirmed papillary thyroid carcinoma within MSO. Thyroid and fertility-preserving surgery were chosen after multidisciplinary consultation. Despite challenges, the patient had a positive outcome with no recurrence after 36 months. Therefore, the adoption of less invasive surgical approaches and vigilant follow-up can achieve remission, but more research is needed to further enhance our understanding of the disease's risk stratification and optimal treatment strategies.