Abstract: Ovarian growing teratoma syndrome (GTS) , as a rare complication, is characterized by the increase in tumor size or tumor number, or both, with the normalization of tumour markers during or after chemotherapy or radiological therapy. Histopathological test showed a mature teratoma without any malignant component. Although the diagnosis is clear, many oncologists often misinterpret because of its rarity. The exact etiology and pathogenesis of this disease are still unclear. Surgery is the best treatment as this disease is resistant to chemotherapy and radiation. We reported a case of GTS, and reviewed relevant literatures, to provide a reference for clinical diagnosis and treatment.

Key words: Teratoma, Diagnosis, Therapy, Case report