Caprine peripheral neuroblastomas: structural and ultrastructural features, intermediate filaments profile and neuro-endocrine characterization.

Abstract

In this report the morphological and immunohistochemical features with respect to intermediate filament proteins and the neuroendocrine nature of bilateral neuroblastomas possibly originating from the adrenal medulla in a goat kid are presented. Histologically, the tumours were composed of small, round, blue cells organized in highly cellular nests and sheets separated by fibrovascular septa. Isolated cells mimicking the morphological features of neurones were observed in both tumours. Ultrastructurally, dense-core neurosecretory granules, about 100 nm in diameter, and irregularly organized neurotubular networks were seen. The small tumour cells were only labelled by vimentin, while the neurone-like cells were labelled by both neurone-specific enolase and synaptophysin. The lack of staining of the tumour cells by the neurofilament proteins antiserum, which was also observed in a human neuroblastoma (used as positive control) has been previously reported and is probably the result of the tissue processing and/or the poor differentiation stage of the tumours. The vimentin labelling of tumour cells could be explained by the poor differentiation stage of the tumours, since vimentin is the only intermediate filament protein in presumptive neuroblasts, being replaced by neurofilament proteins in later stages of neurogenesis.