Resistant
hypertension is often difficult to treat and may be associated with underlying primary
aldosteronism (PA). We describe the case of an elderly gentleman who presented with severe and resistant
hypertension and was found to have a left
adrenal incidentaloma during evaluation but had
aldosterone excess secondary to unilateral adrenal
hyperplasia (UAH) of the contralateral gland, which needed surgical intervention. A 65-year-old gentleman was evaluated for uncontrolled
high blood pressure (BP) in spite of taking four
antihypertensive medications. The high BP was confirmed on a 24-h ambulatory reading, and further biochemical evaluation showed an elevated serum
aldosterone renin ratio (ARR) (1577 pmol/l per ng per ml per h). Radiological evaluation showed an adrenal nodule (15 mm) in the left adrenal gland but an adrenal vein sampling demonstrated a lateralization towards the opposite site favouring the right adrenal to be the source of excess
aldosterone. A laparoscopic right
adrenalectomy was performed and the histology of the gland confirmed nodular
hyperplasia. Following surgery, the patient's BP improved remarkably although he remained on
antihypertensives and under regular endocrine follow-up. PA remains the most common form of secondary and difficult-to-treat
hypertension. Investigations may reveal incidental adrenal lesions, which may not be the actual source of excess
aldosterone, but UAH may be a contributor and may coexist and amenable to surgical treatment. An adrenal vein sampling should be undertaken for correct lateralization of the source, otherwise a correctable diagnosis may be missed and the incorrect adrenal gland may be removed.
LEARNING POINTS: Severe and resistant
hypertension can often be associated with underlying PA.ARR is an excellent screening tool in patients with suspected PA.Lateralization with adrenal venous sampling is essential to isolate the source and differentiate between unilateral and bilateral causes of
hyperaldosteronism.Adrenal incidentalomas and UAH may coexist and the latter may often be the sole cause of excess
aldosterone secretion.Decisions about
adrenalectomy should be made only after integrating and interpreting radiological and biochemical test findings properly.