Endocrine Abstracts

A 74-year-old man was referred urgently for investigation of recurrent phaeochromocytoma.

In 2006, he was referred to another hospital with nocturnal sweating and tremors. He was found to have a left sided phaeochromocytoma which was removed laparoscopically with uneventful follow up. Unfortunately no initial results or histology were available on referral to our department.

Follow up in primary care had involved annual 24 h urinary catecholamines but no imaging. The patient had remained well with no recurrence of his symptoms and stable blood pressure. Routine annual collection in 2010 revealed a striking abnormality in biochemistry. On examination the patient was well and reported no symptommatology with blood pressure 125/73 mmHg.

He was urgently referred for management of his recurrent phaeochromocytoma.

Plasma metanephrines were reassuringly normal with normetadrenaline 0.48 nmol/l and metadrenaline 0.16 nmol/l (<1.3 and <0.7 nmol/l respectively indicate low probability of phaeochromocytoma).

On direct questioning of the patient he had been diagnosed earlier in the year with Parkinson’s disease and started on co-Beneldopa with the dose gradually titrated up.

Drug interactions in the case of investigation of phaeochromocytoma with 24 h urinary catecholamines are well documented. In this case the cause for a sudden and dramatic rise in the urinary catecholamines was revealed by detailed history taking and spared the gentleman unnecessary further investigation. Questioning of changes in medication and dosing should be routine in every clinical assessment.

We will be following up this gentleman with annual plasma metanephrines.