Intracranial tumours in budgerigars

In a retrospective study of 996 budgerigars 14 intracranial tumours were examined histologically and immunocytochemically. Tumours of the ependyma (6), choroid plexus (1), adenohypophysis (6) and one unclassified tumour were found. Immunostaining was applied using antibodies against glial fibrillary acidic protein, vimentin, cytokeratin, neuron specific enolase, neurofilament-200 and S-100 protein. The presence of hormones in pituitary tumours was also tested by immunocytochemistry with antibodies to adrenocorticotrophic hormone, melanocyte-stimulating hormone, prolactin and growth hormone. Positive immunostaining was found in two carcinomas of the adenohypophysis using anti-growth hormone antibody and, by using anti-S-100 antibody, in the cytoplasm of several cells of the remaining tumours. There was no immunoreactivity in either normal or neoplastic tissues of budgerigars with anti-glial fibrillary acidic protein, anti-vimentin, anti-cytokeratin and anti-neuron specific enolase antibodies. With anti-neurofilament-200 antibody, positive immunoreactivity was found in neuronal fibres of normal brain but not in neoplastic tissue.