Excretion by Patients with Neural Crest Tumors

VMA and HVA excretion by 29 patients with neural crest tumors. From these data, we offer preliminary observations on the validity of applying our procedure to the investigation of patients suspected of having a neural crest tumor. Column maintenance: The useful life of the column can be approximately doubled by adopting the following procedure for column maintenance. At the end of each working day, wash the column successively with 20 mL of each of the following: de-ionized water; 1-heptanesulfonic acid (Eastman Kodak), 2 mmol/L in phosphate buffer (70 mmol/ L, pH 4.8); de-ionized water; and, finally, methanoL Strict adherence to this procedure increases column life to about 10 weeks, or 300 analyses. Reference ranges: Table 1 lists 95th and 100th percentile reference values for urinary excretion of VMA and HVA. The values for HVA are very similar to those recently reported by other investigators (2,3). Those for VMA are similar to those reported by de Schaepdryver et al. (2), but are appreciably lower than those reported by Haymond et al. (4), who used the method of Pisano et aL (5). Patients with neural crest tumors: We measured urinary VMA and HVA excretion in 15 patients with neuroblastoma and 16 patients with pheochromocytoma (Table 2). A comparison with the reference values in Table 1 shows that VMA excretion (in mg/24 h) by all 31 of the patients exceeded the 100th percentile value-i.e., there was no overlap in VMA excretion between individuals with and without neural crest tumors. These data contrast