Immunocytochemical studies in canine neuroectodermal brain tumors

Abstract

Seventy-four canine neuroectodermal tumors were examined immunocytochemically for the presence of glial fibrillary acidic protein (GFAP). Eleven oligodendrogliomas were examined for the presence of myelin basic protein (MBP) and myelin-associated glycoprotein (MAG). Twenty-three tumors, including ten astrocytomas, one ependymoma, two glioblastomas, one case of gliomatosis, and nine poorly differentiated gliomas were positive for GFAP. Two astrocytomas, eleven oligodendrogliomas, eight ependymomas, four choroid plexus papillomas, two medulloblastomas, one glioblastoma, nine poorly differentiated gliomas, six cases of gliomatosis, and three unclassified tumors were GFAP-negative. In six tumors (including four that were classified as astrocytoma) GFAP staining was equivocal. All oligodendrogliomas were MBP-negative but three expressed MAG. It was concluded that many canine gliomas are not only morphologically but also immunocytochemically similar to human gliomas, but that a larger proportion of canine neuroectodermal growths are undifferentiated tumors.

Immunohistochemical Demonstration of Keratin in Canine Neuroepithelioma

“…Similar results for GFAP in canine ependymomas have been reported. 21 In contrast, human ependymomas stain for GFAP and NSE.4, 22 The lack of immunoreactivity with GFAP and NSE in neuroepitheliomas could be due to the high degree of cellular undifferentiation in this tumor. Alternatively, absence of immunoreactivity with GFAP and NSE could indicate a non-neuroectodermal origin, e.g., extrarenal nephroblastoma or teratoma.…”

Anaplastic Ependymoma in the Cervical Spinal Cord of a Maltese Dog

“…GFAP immunoreactivity of ependymoma has been reported to be positive in humans, cats, and horses [3,6,7], but most canine ependymoma including this case were negative for GFAP [1,14]. The reason for the negative finding for GFAP in canine cases is unknown.…”

Aberrant E-cadherin, β-catenin, and glial fibrillary acidic protein (GFAP) expression in canine choroid plexus tumors

“…7,28 However, a large proportion of CPPs and CPCs strongly expressed GFAP in contrast to previous studies on canine CPTs, in which most tumors did not express GFAP. 7,27,35 In comparison, GFAP immunoreactivity has been reported in 25-58% of human CPTs. 2,28,32 The presence of GFAP in CPTs has been interpreted as evidence of local ependymal differentiation of neoplastic cells.…”