RESUMO
The immature teratoma is the 3rd most common germ cell tumor and represents 10-20% of all ovarian malignancies occurring in the first two decades of life. The initial clinical manifestation is abdominal/pelvic mass with pain. This tumor is usually unilateral and large, and has a prominent solid component with cystic elements. It is composed of mature and immature tissues derived from the three germ cell layers. Tumor grading is based on the amount of immature tissues which mostly derives from neuroectodermal origin. The prognosis and treatment depend on the clinical stage and histological grade of the tumor. The initial treatment should include unilateral salpingo-oophorectomy and removal of as much extraovarian tumor as possible. Adjuvant chemotherapy is not necessary for the patients with stage IA, grade 1 tumor or those with mature glial implants. Combination chemotherapy is recommended for the patients with grade 2 or 3 tumors or those with immature metastases. Although the immature teratoma was considered aggressive tumor type before the prevalent use of chemotherapy, the advances in combination chemotherapy have leaded to the better prognosis than before. We have experienced three cases of immature teratoma and report them with brief review of literatures.