INTRACRANIAL OLFACTORY NEUROBLASTOMA - EVIDENCE FOR OLFACTORY EPITHELIAL ORIGIN

Aims: To determine the possible histogenesis of the intracranial variant of olfactory neuroblastoma. Methods: Four specimens from three cases of intracranial olfactory neuroblastoma were studied by light microscopy and immuno-histochemistry, and electron microscopy in two cases. Results: Light microscopical examination showed small cell tumour with additional features of epithelioid cells in one case and ganglion cells in another. Olfactory and Homer-Wright rosettes were present. All the specimens showed a uniform positive reaction to neurone specific enolase, S-100, and cytokeratin antibodies. Glial fibrillary acidic protein was absent. The salient electron microscopic features were the presence of cell junctions, cytoplasmic intermediate filaments, basal bodies and cytoplasmic processes. Dense cored vesicles were absent. Conclusions: The results strongly support the view that intracranial olfactory neuroblastomas are of olfactory epithelial origin and differ from conventional neuroblastomas.