Random urine samples were obtained from 31 patients with
neuroblastoma (newborn to 8 yr of age) and from 100 children without this
tumor (newborn to 10 yr). The urine samples were studied for the presence of
sulfate and
glucuronide conjugates of homovanillic (HVA), dihydroxyphenylacetic, vanilmandelic, and vanillactic
acids. The urinary concentrations of these
acids were determined by capillary gas-chromatography before and after enzymatic treatment with
glucuronidase and
sulfatase. Concentrations of the "free" fraction and "total" urinary content of these
acids were determined using the results from untreated and treated urines respectively. Age-related reference values were established for children without
neuroblastoma. Fractions of the total content of urinary HVA (18-39%) and dihydroxyphenylacetic
acid (36-66%) were excreted as
glucuronides and/or
sulfates by the control group, with the highest conjugated fractions found in the urine of young infants (0-3 months). Vanilmandelic was excreted mainly as "free"
acid (unconjugated), whereas
vanillactic acid was undetectable in almost all control samples. Patients with
neuroblastoma also excreted a fraction of these
acids as
glucuronide and/or
sulfate conjugates, (25% of urinary HVA, 39% of dihydroxyphenylacetic
acid and 45% of
vanillactic acid) whereas
vanilmandelic acid was excreted only as "free" in controls. Determination of "total" rather than "free" urinary HVA was diagnostic in one
neuroblastoma patient with borderline "free" HVA levels, whereas determination of "free" or "total" dihydroxyphenylacetic
acid and
vanillactic acid did not improve the diagnostic sensitivity in the cases examined. We conclude that it may be clinically useful to determine "total" urinary HVA in patients with borderline "free" HVA levels who are suspected of having
neuroblastoma.