Chromogranin A, secretogranin II and vasoactive intestinal peptide in phaeochromocytomas and ganglioneuromas.

By means of immunohistochemistry we analysed the distribution of chromogranin A, secretogranin II and vasoactive intestinal peptide (VIP) in 16 phaeochromocytomas, two cases of combined phaeochromocytoma-ganglioneuroma and four adrenal ganglioneuromas. Chromogranin A was found in the majority of phaeochromocytes and in mixed phaeochromocytomas-ganglioneuromas. Secretogranin II was present to a lesser degree in phaeochromocytes, but strong immunostaining was found in most ganglion cells of phaeochromocytomas, in the ganglioneuroma component of combined tumours and in adrenal ganglioneuromas. Vasoactive intestinal peptide was present in some ganglion cells of phaeochromocytomas, in the ganglioneuroma component of mixed tumours and in three of four adrenal ganglioneuromas. On semi-adjacent sections a co-localization of VIP and secretogranin II was demonstrated. These results indicate that neuronal differentiation is accompanied by an increased immunohistochemical expression of secretogranin II. Therefore, secretogranin II may be a useful marker for ganglion cell differentiation.