Endocrine Abstracts

Background: A 58-year-old male known to have hypertension since 2002 was initially treated with Furosemide and Bendroflumethiazide but was stopped due to hypokalemia. Blood pressure was controlled with Ramipril, Atenolol, Doxazocin and Amlodepine. He was found to be persistently hypokalemia ranging from 2.7 to 3.3 mmol/l.

Investigations: Aldosterone: 250 ng/l, renin: <2.3 mU/l, aldosterone:renin ratio: >108, 24 h urine catecholamines×2: normal CT scan (Oct 2010) – 8 mm right adrenal adenoma MRI (Jan 2011) – right adrenal gland was not clearly seen due to movement artefact.

Discussion: This man had biochemical evidence of primary hyperaldosteronism. Initial CT scan showed evidence of right adrenal adenoma but adrenal vein sampling showed that the hyperaldosteronism originated from the left adrenal gland. This case demonstrates the value of using adrenal vein sampling to localise the hyperfunctioning gland in the absence of definitive and potentially misleading adrenal imaging.