LAUSR

Ependymomas are well-demarcated and slow-growing neuroepithelial neoplasms that comprise 3–9% of primary CNS tumors. The vast majority of ependymomas arise either intracranially, mostly in children, or in the spinal cord and are associated with ependymal lining. Histologic hallmarks are perivascular pseudorosettes, ependymal rosettes and alternating zones of nuclear crowding and nuclear free zones composed of coarse cell processes. In high grade ependymomas increased mitoses, necrosis and nuclear pleomorphism may be seen. We present the case of a 63-year-old woman in with a past medical history of retinopathy of prematurity, glaucoma and right eye enucleation. She presented with a painful blind left eye refractory to medical treatment and subsequently underwent left eye enucleation. On histologic examination, an incidental retinal ependymoma was identified. The neoplastic cells were fusiform and had long coarsely fibrillar cell processes. Characteristic periodicity of nuclear crowding and scarcity was observed. In places, neoplastic cell processes extended radially to delicate and sometimes hyalinized blood vessels, forming so-called perivascular pseudorosettes. Definite ependymal rosettes were not recognized in the examined sections. Stigmata of chronicity were found, such as ischemic type necrosis, blood vessels with dystrophic calcifications and foci of ossification replete with fibroadipose tissue in the marrow spaces. The neoplastic cells labeled with antibodies against glial fibrillary acidic protein (GFAP), thus confirming glial lineage in the neoplastic cell. Additionally, there was scattered intracytoplasmic expression of epithelial membrane antigen (EMA) in a dot-like or circular pattern. The latter is well described in ependymomas and often used to support the diagnosis. Ependymomas rarely occur at extracranial sites, such as the chest, abdomen and pelvis. We are presenting the fourth case of retinal ependymoma reported in literature. The tumor had classical immunomorphologic findings.