HISTOPATHOLOGICAL AND IMMUNOHISTOCHEMICAL STUDIES OF INTRACRANIAL NERVOUS-SYSTEM TUMORS IN 4 CATTLE

Intracranial nervous-system tumours were diagnosed in three of 1092 bo vine necropsy specimens submitted to the Department of Veterinary Path ology, Obihiro University between April 1983 and March 1996. A fourth case was a referral from the Department of Veterinary Pathology, Rakun o Gakuen University. Histopathological examination revealed four types of tumour; intracranial malignant peripheral nerve sheath tumour (MPN ST), choroid plexus papilloma, differentiated fibrillary astrocytoma a nd anaplastic (malignant) astrocytoma. Immunohistochemically, the intr acranial MPNST was strongly positive for S-100 protein and vimentin, a nd in places weakly positive for glial fibrillary acid protein (GFAP). The choroid plexus papilloma was strongly positive for epithelial mem brane antigen (EMIA), keratin, S-100 protein and vimentin, and positiv e for GFAP in places. The cytoplasm and fibrous component in the diffe rentiated fibrillary astrocytoma were strongly positive for S-100 prot ein and GFAP. The anaplastic (malignant) astrocytoma was strongly posi tive for vimentin, S-100 protein and keratin in the cytoplasm and fibr ous processes, and weakly positive for GFAP and EMA in places. Myelin basic protein (MBP) and synaptophysin showed a weak positive reaction in the marginal areas of the tumour. (C) 1998 W.B. Saunders Company Li mited