Ependymomas are an uncommon glial tumors that usually arise from the central nervous system but they can occasionally occur in various extra-axial regions. Pure ovarian ependymoma, classified as differentiated glioma, was first described by Kleinman et al in 1984 and only a few cases have been reported since then. A 48 year-old multiparous woman with the diagnosis of left adnexal mass underwent surgery. Macroscopic evaluation of the left ovary showed 11x8 cm sized smooth-walled mass. Microscopic examination revealed small to medium sized cells with hyperchromatic, round to oval nuclei and scanty cytoplasm, perivascular pseudorosettes. Immunohistochemical staining for GFAP, vimentin, estrogen and progesterone receptors were positive. Based on these histopathologic and immunohistochemical features, the tumor was diagnosed as an ovarian ependymoma. As they seem rare, there is no verified treatment modality for ovarian ependymomas. , it is important to report these rare tumors, to shed light to the management and follow-up of them. To establish standard treatment modalities for neuroectodermal tumors of the ovary, it is essential to discuss all cases of ovarian epenymoma in the literature.
Key words: Ependymoma, ovarian, immunohistochemistry