Phaeochromocytomas diagnosis

Collinson PO, Kind PR, Slavin B, Weg MW, Sandler M. False diagnosis of phaeochromocytoma in patients on Sinemet. Lancet 1984 1 1478-9. 

Quinn N, Carruthers M. False positive diagnosis of phaeochromocytoma in a patient with Parkinson s disease receiving levodopa. J Neurol Neurosurg Psychiatry 1988 51 728-9,... 

In MEN type Ha. medullary carcin-omaof thyroid is present with hyperparathyroidism and bilateral adrenal phaeochromocytomas. Medullary carcinoma of thyroid is diagnosed on the basis of elevated calcitonin concentrations in serum, although provocation tests, such as a calcium infusion and/or administration of pentagastrin. may be necessary to demonstrate the abnormal calcitonin regulation (Fig., 1). Diagnosis of phacochromocytoma is not easy (p. 126). 

The patient s plasma PTH should be measured and, if increased, a diagnosis of primary hyperparathyroidism can be made. However, hyperparathyroidism with a serum calcium of 2.8 mmol/1 is usually asymptomatic and thus another cause for his hypertension, headaches and anxiety should be sought. If the symptoms were episodic this would suggest the possibility of a phaeochromocytoma which is associated with hyperparathyroidism in families with MEN. The patient should have his urinary catecholamines measured and, if the diagnosis is made, it is important that other members of his family be screened for hyperparathyroidism and phaeochromocytoma. 

Homovanillic and vaniUylmandehc acids, the major metabolites of catecholamines, are often tested in urine for neurological diagnosis and for monitoring the response to therapy in diseases such as phaeochromocytoma and neuroblastoma. 

According to Schumann,a 24 hr excretion of more than 50 g of noradrenaline-H adrenaline supposes the existence of a phaeochromocytoma. With regard to a differential diagnosis, all those illnesses listed in Table 3 (pp. 26-56) have to be considered where an increased excretion of catecholamines or their metabolites occurs. The consumption of food which contains catecholamine (e.g. bananas, potatoes, chocolate, coffee) should not lead to an increased excretion of the amines themselves, but it may slightly increase the excretion of their metabolites. 

Sandler, M. and Ruthven, C. R. J., Quantitative colorimetric method for estimation of 3-methoxy-4-hydroxymandelic acid in urine value in diagnosis of phaeochromocytoma, Lancet, 1959, p. 114. 

The diagnosis of neural tumours such as phaeochromocytoma and neuroblastoma is heavily dependent on the laboratory measurement of urinary levels of methylated catecholamines and of their two acidic catabolites, 4-hydroxy-3-methoxymandelic acid (VMA) and 4-hydroxy-3-methoxyphenyl acetic acid (HVA). 

---