Background: Histopathologic diagnosis and treatment of ovarian anaplastic ependymoma are challenging.
Case: A 61-year-old-woman presented with a 10-cm right adnexal tumor associated with peritoneal carcinomatosis extending to the right diaphragm and liver surface. After initial diagnosis of a papillary serous carcinoma, we performed extensive but nonoptimal cytoreductive surgery including hysterectomy with bilateral oophorectomy. Histology revealed some axially arranged cells with a prominent fibrillary cytoplasm, suggesting an ependymoma. Diagnosis was confirmed by immunophenotype showing strong positivity to glial fibrillary acidic protein. Given the strong tumoral expression of estrogen and progesterone receptors, an aromatase inhibitor was initiated. One year later, computed tomography scan showed stability of the residual peritoneal nodules.
Conclusion: Aromatase inhibitor treatment could be effective in cases of extraaxial ependymoma with prominent estrogen receptor expression.