In a n attempt to define a biochemical test which would be helpful in the care of individuals with malignant melanoma, urinary excretion of DOPA, homovanillic acid, dopamine, norepinephrine, epinephrine, and 3-methoxy-4-hydroxymandelic acid of 16 patients with advanced disease was measured. Abnormally high levels were found in only one half of the cases, the pattern varying among the patients. DOPA was the single compound which was most frequently excreted in large amounts. Preliminary studies suggest that serial determinations of DOPA may be useful i n following response to therapy of those patients whose melanoma is associated with increased DOPA output.
HE NEUROBLASTOMA, PHEOCHROMOCYTOMA
T and melanoma are embryologically related tumors derived from cells of neural crest origin. T h e neuroblastoma arises from sympathetic nervous tissue which synthesizes dopamine and norepinephrine. T h e pheochromocytoma is composed of chromaffin cells which produce norepinephrine and epinephrine. Measurements of the urinary excretion of these catecholamines and their metabolites are recognized as valuable aids in the diagnosis and follow-up care of patients with these 2 tumors. Abnormally high levels of the various compounds are found when neoplastic tissue is present, and values fall to the normal range after surgical removal of tumor or its destruction by radiation therapy or chemotherapy. Sometimes these biochemical analyses indicate the presence of residual or recurrent disease when other methods of diagnosis fail.
Melanomas are malignant tumors arising