Correlation between tyrosine hydroxylase immunoreactive cells in tumors and urinary catecholamine output in neuroblastoma patients.

The results of an immunocytochemical evaluation of tyrosine hydroxylase (TH) immunoreactivity in 30 neuroblastic tumors of infancy are reported. Although no correlations could be found between the immunoreactive pattern and the site of origin or the staging of the tumor, a positive relationship between the urinary catecholamine output and the density of TH-immunoreactive cells could be established. TH was mostly localized on the cytoplasm of the differentiating neuroblasts, whereas immature elements were rarely positive. Moreover, 2 stage IVS cases did not contain any TH immunoreactivity. The possible significance of this finding in the investigation of this form of neuroblastoma, which has a peculiar biological behavior, is considered.