Catecholaminergic differentiation associated with S100 protein-positive elements in human neuroblastoma

The intratumorous distribution of catecholaminergic tumour cells and S100 protein-positive elements of 8 neuroblastomas, 8 ganglioneuroblastomas and 2 ganglioneuromas were studied using catecholamine fluorescence and immunohistochemical staining, respectively. The elements of catecholamine fluorescence were observed in all tumour specimens, even in urinary VMA-negative cases, but the patterns of distribution were not uniform. Catecholamine fluorescence was observed in both tumour cell bodies and neurofibres, and the appearance of the latter but not that of the former correlated with the histological grade of differentiation, thereby suggesting the occurrence of catecholaminergic differentiation within the tumour. S100 protein-positive elements also correlated with the histological differentiation, and were distributed mostly in the area where the catecholamine-containing neurofibres were located. The possible correlation between catecholaminergic differentiation and the appearance of S100 protein-positive elements in neuroblastoma requires close attention.