Malignant Dysembryoplastic Neuroepithelial Tumour in a Zebrafish (Danio rerio)

摘要

Neuroectodermal tumours in man, including medulloblastoma, medulloepithelioma, neuroblastoma, esthesio-neuroblastoma, primitive neuroectodermal tumour and dysembryoplastic neuroepithelial tumour, typically occur in children and young adults. These tumour types are occasionally observed in juvenile and adult zebra-fish (Danio rerio) either as induced tumours in carcinogen-exposed zebrafish or as an incidental finding in zebrafish >= 2 years of age. An adult zebrafish submitted for routine histologicalexamination was sent for a second opinion consultation after an uncharacteristic brain mass was identified. Microscopically, the expansile and infiltrative extracortical mass arising from the cerebellum had a diffuse microcystic pattern with solid hypercellular regions occupying 80% of the extrameningeal space and effacing the endomeninx and significantly displacing the metencephalon. The mass was composed of dense sheets of oligodendrocyte-like cells, random neurons and pseudocysts containing 'floating neurons' within a scant mucinous matrix. Neoplastic cells demonstrated positive perinuclear and intracytoplasmic expression of S-100. Malignant dysembryoplastic neuroepithelial tumour was diagnosed based on the histological features of the brain mass,which were indistinguishable from the human tumour. To our knowledge, this is the first report of a dysembryoplastic neuroepithelial tumour in a zebrafish.