Histopathological and immunohistochemical characteristics of ventricular ependymoma in a goat

Ependymomas as primary central nervous system neoplasms are occasionally observed in human infants however; they are rare in animals. A three-year-old male goat was presented with clinical neurological signs. At necropsy, a 3×2×2 cm, bulging, white-grey- to red, soft mass extending into the left lateral ventricle of brain was observed. Microscopically, the mass with densely cellular population was nonencapsulated, mostly containing cuboidal-columnar neoplastic cells with pseudo-rosettes formation. Mitotic figures were rare and malignancy indexes were not observed. Neoplastic cells were immunohistochemically positive for Glial Fibrillary Acidic Protein (GFAP), S-100, and vimentin; however, they did not express Cytokeratins. On the basis of the location, histologic and immunohistochemical findings, the tumor was diagnosed as an ependymoma.