New Immunohistochemical Markers in the Diagnosis of Neuroendocrine Neoplasms

Neuroendocrine neoplasms are relatively rare tumours whose biological behaviour ranges from indolent to very aggressive with high lethality rate. A significant proportion of them arise in the background of hereditary syndromes or are associated with the occurrence of other tumours. The most accurate diagnosis and detection of these syndromes is critical for further patient management. My work focuses on the testing of new immunohistochemical markers for the diagnosis of paragangliomas, which is currently based on the absence of cytokeratin expression, the demonstration of a neuroendocrine phenotype and the expression of GATA3 or tyrosine hydroxylase. A reliable sensitive and specific marker of paraganglioma is lacking in routine pathology. Phox2B and Hand2 are transcription factors involved in embryogenesis of the autonomic nervous system that are critical for the development of the terminal chromaffin cell phenotype. The Phox2B antibody is used for the diagnosis of neuroblastoma and has been investigated in the past in the differential diagnosis of neuroendocrine neoplasias with rather conflicting results. The Hand2 antibody has not yet been studied in neuroendocrine neoplasia in pathology. We tested the immunoreactivity of both antibodies in a cohort of 340 neuroendocrine neoplasms and other...