Vasoactive intestinal peptide and its relationship to ganglion cell differentiation in neuroblastic tumors.

Immunohistochemical studies have demonstrated that immunoreactive vasoactive intestinal peptide is present in, and restricted to, the differentiating and mature ganglion cells in a variety of normal and neoplastic neural tissues. In a composite pheochromocytoma-ganglioneuroma (associated with the syndrome of watery diarrhea, hypokalemia, and hypochlorhydria), five ganglioneuroblastomas, five ganglioneuromas (two of which were associated with diarrheal syndromes), an unusual mixed neuroblastoma-ganglioneuroma, and four normal sympathetic ganglia, vasoactive intestinal peptide was present in differentiating and mature ganglion cells. The peptide was also demonstrated in isolated ganglion cells in two pheochromocytomas but was not present in pheochromocytes, Schwann cells, or undifferentiated neuroblastic cells in the neuroblastomas and ganglioneuroblastomas. These studies indicate that the presence and presumably the production of vasoactive intestinal peptide thus reflect a particular line of neuroblastic differentiation and are not merely a reflection of common derivation of these tissues. Our identification of vasoactive intestinal peptide in neurogenic tumors associated with diarrhea supports the contention that the peptide might be an important diarrheogenic factor in these tumors.