Nestin as a diagnostic and prognostic marker: immunohistochemical analysis of its expression in different tumours.

The designation NESTIN refers to a member of the family of intermediate filaments and comes from the fact that this protein is expressed mainly in neuroepithelial stem cells. However, nestin is not expressed in mature elements and terminal cell differentiation is associated with loss of immunoreactivity to this protein. Therefore, immunohistochemical assessment of nestin expression might be useful to differentiate between mature and immature elements. The aim of this study was to analyse nestin expression in various tumours of neuroectodermal and vascular origin and to determine whether its detection has practical relevance. The results indicate that the immunohistochemical detection of nestin expression could be useful in astrocytomas and malignant melanomas, where it could be used as an auxiliary indicator of dedifferentiation and progression. Because of the weak and heterogeneous expression of nestin in neurinomas, phaeochromocytomas, and carcinoids, nestin detection in these lesions is of little practical use.