A case report of a young girl with mucinous borderline tumor of the ovary.

Ovarian tumors are relatively rare in children and adolescent. The incidence of malignancies in these groups is 1% to 1.5%. The common histologic type is non-epithelial type such as germ cell tumors or sex cord-stromal tumors and only 10% to 17% of those are epithelial tumors. It is important to accurately diagnose in the early these rare tumors for proper staging and treatment to save the patient's life and fertility. We present a case of a 13-year-old girl with a giant ovarian mucinous borderline tumor.