Use of plasma metanephrine to aid adrenal venous sampling in combined aldosterone and cortisol over-secretion

[摘要] In patients with primary aldosteronism (PA) undergoing adrenal venous sampling (AVS), cortisol levels are measured to assesslateralization of aldosterone overproduction. Concomitant adrenal autonomous cortisol and aldosterone secretion thereforehave the potential to confound AVS results. We describe a case where metanephrine was measured during AVS to successfullycircumvent this problem. A 55-year-old hypertensive male had raised plasma aldosterone/renin ratios and PA confirmed byfludrocortisone suppression testing. Failure of plasma cortisol to suppress overnight following dexamethasone and persistentlysuppressed corticotrophin were consistent with adrenal hypercortisolism. On AVS, comparison of adrenal and peripheral A/Fratios (left 5.7 vs peripheral 1.0; right 1.7 vs peripheral 1.1) suggested bilateral aldosterone production, with the left glanddominant but without contralateral suppression. However, using aldosterone/metanephrine ratios (left 9.7 vs peripheral 2.4;right 1.3 vs peripheral 2.5), aldosterone production lateralized to the left with good contralateral suppression. The patientunderwent left laparoscopic adrenalectomy with peri-operative glucocorticoid supplementation to prevent adrenalinsufficiency. Pathological examination revealed adrenal cortical adenomas producing both cortisol and aldosterone within abackground of aldosterone-producing cell clusters. Hypertension improved and cured of PA and hypercortisolism wereconfirmed by negative post-operative fludrocortisone suppression and overnight 1 mg dexamethasone suppression testing.Routine dexamethasone suppression testing in patients with PA permits detection of concurrent hypercortisolism which canconfound AVS results and cause unilateral PA to be misdiagnosed as bilateral with patients thereby denied potentially curativesurgical treatment. In such patients, measurement of plasma metanephrine during AVS may overcome this issue.

[学科分类] 血液学

[关键词] Adult;Male;White;Australia;Adrenal;Adrenal;Aldosterone;Cortisol;ACTH;Metanephrines;Hyperaldosteronism;Hypertension;Cushing's syndrome;Adrenocortical adenoma;Hypertension;Hypokalaemia;Adrenal venous sampling;Metanephrines (plasma);Cortisol;Aldosterone (blood);Blood pressure;Immunohistochemistry;Dexamethasone suppression;Fludrocortisone suppression;Aldosterone to renin ratio;CT scan;Potassium;Creatinine (serum);Sodium;Glucose (blood;fasting);Ultrasound scan;Adrenal antibodies;Adrenalectomy;Laparoscopic adrenalectomy;Glucocorticoids;Hydrocortisone;Glucocorticoids;Cortisone acetate;Corticosteroids;Novel diagnostic procedure;November;2015