Bond, J.V. (1975). Archives of Disease in Childhood, 50, 691. Clinical significance of catecholamine excretion levels in diagnosis and treatment of neuroblastoma. The pattern of urinary excretion of vanillylmandelic acid (VMA) was studied in 50 children with neuroblastoma. There were 10 disease-free survivors, and 4 children who survive for 3 or more years with residual nonmetastatic disease, 36 children died with widespread metastic disease. The urinary VMA level was raised at diagnosis in 8 of the 10 disease-free survivors but rapidly returned to normal after treatment. In 3 out of 4 children with residual tumour, VMA remains persistently raised. In 28 of the 36 children who died VMA was raised at diagnosis and remained so throughout the course of their disease. In the majority of the children with metastatic disease the finding of a raised VMA revealed the nature of the primary tumour. Measurement of urinary VMA is a simple diagnostic test which confirms the presence of neurblastoma and avoids the need for more complex investigations. The prompt return to normal levels in the disease-free survivors confirms the importance of serial VMA estimations in assessing response to treatment and ultimate prognosis. The other good prognostic features in the surviving patients were young age at diagnosis, primary tumour in the thorax, and histologically well-differentiated tumours which had not metastasized.