Divergent differentiation in neuroendocrine tumors of the adrenal gland

Composite tumors of the adrenal medulla usually consist of pheochromoctytom a admired with ganglioneuroma or ganglioneuroblastoma. These neoplasms refl ect phenotypic plasticity shown by primitive sympathetic cells and mature c hromaffin cells in vitro. They may give rise to metastatic neuroblastoma in adults and may cause signs and symptoms attributable to both catecholamine and neuropeptide production. Schwann cells and sustentacular cells are typ ically numerous in these tumors but it is not known whether they are neopla stic. Immunohistochemical staining for catecholamine biosynthetic enzymes, secretory vesicle proteins and S-100 protein tends to recapitulate staining of the normal adrenal medulla or sympathetic ganglia. Sparsity of chromogr anin A in the cell bodies of immature and mature neurons is a diagnosticall y useful characteristic. Copyright (C) 2000 by W.B. Saunders Company.