Catecholamines: Adrenaline/Noradrenaline/Dopamine
Biochemistry Overview / Directory
Purpose of the test
Phaeochromocytoma is a slow growing tumour which may be found in the adrenal medulla or extra-adrenally. Associated with hypertension unresponsive to conventional treatment, symptoms may be non-specific e.g. headaches, anxiety, tachycardia etc. Benign in 90% of cases identification of a phaeochromocytoma is important as it is a potentially curable cause of hypertension. Free catecholamines are the most reliable test to identify phaeochromocytomas. Phaeochromocytoma is also associated with the multiple endocrine neoplastic syndromes (MENs) and neurofibromatosis. In tumours located in the adrenal medulla adrenaline is the catecholamine primarily secreted, whereas in extra-medullary phaeochromocytomas both adrenaline and noradrenaline are produced. Thus, free catecholamine measurements may be useful in guiding subsequent imaging or radioisotopic studies.
Dopamine is increased in children with neuroblastomas due to production by the tumour. Some neuroblastomas also produce noradrenaline. These tumours may arise in neural crest tissue and can be located anywhere in the abdomen, often close to or surrounding the spinal cord. Most are malignant producing metastases to the liver, but the Type IV-S found in the first year of life appear to often regress spontaneously. Urinary dopamine concentrations appear to correlate with tumour burden and sequential measurements can be useful in monitoring therapy.
Sample Requirements
Timed (24h) urine collections are preferred for investigations of adults for phaeochromocytoma or carcinoid syndrome. Samples should be collected into plain containers or into acid containing bottles. Acidification of the sample prior to despatch provides greater stability for the analytes measured. A 10-25 mL aliquot is preferred with the 24h urine volume provided. Random samples can be collected in children under investigation for a neuroblastoma and age-specific reference ranges will be applied.
Storage and Transport
Send by overnight first class post.
Turnaround Time
Assays for catecholamines are carried out daily and a turnaround time of 1-2 weeks is typical. Markedly abnormal results will be telephoned or Faxed
Price
Price available on application - please contact adrian.turner@kch.nhs.uk. Discounts could be available for significant workloads.
Contacts
Dr Roy Sherwood
Tel: 020 3299 3726
e-mail: roy.sherwood@nhs.net
or
Mr Colin Stone
Tel: 020 3299 4121
e-mail: colin.stone@kch.nhs.uk
