Endocrine Abstracts

Introduction: Aldosterone producing adenoma, called Conn syndrome, accounts for 10 percent of all hypertension cases. It should be remembered in patients with hypokalemia and hypertension however, this is not a rule. Conn syndrome can be presented with hypertension but normal potassium levels. Also, rarely it can be presented with hypokalemia but normal blood pressure as in our case.

Case report: 34-year-old female patient complained about difficulty in walking and trips and falls without a cause. Assessment in neurology clinic revealed low potassium levels (2.6 meq/l) and normal sodium levels in the upper limit (141 meq/l). The patient is referred to our clinic. Abdominal ultrasound showed a 12×6 mm hypoechoic nodule in the right adrenal zone consistent with adrenal adenoma. She denied history of hypertension. Family history did not suggest Conn syndrome. Aldosterone levels were 257 pg/ml, plasma renin activity was 0.45 ng/ml/h, aldosterone/renin ratio was 57.1 after correction of serum potassium levels. Two controls gave similar results. Cortisol level was 15.61 μg/dl, ACTH level was 25.9 pg/ml. Cortisol levels were suppressed to <1.8 μg/dL after 1 mg dexamethasone suppression test. 24-hour urinary cortisol level was 37 μg/day (3.5–45). DHEAS level was 159 μg/dl (35–430). 24-h ambulatory blood pressure revealed a median blood pressure of 125/85 mm/Hg. Computed tomography for adrenal gland showed 16x10 mm lesion in right adrenal gland medial crus with a HU density of −2 which is consistent with adrenal adenoma. Left adrenal gland was normal. The patient was referred to surgery for aldosterone producing unilateral adrenal adenoma and undergone right adrenalectomy. The postoperative pathology was consistent with adenoma. The patient did not need potassium replacement after two days, as potassium levels were normal.

Discussion: Diuretic treatment, Bartter syndrome and persistent vomiting can cause hypokalemia without hypertension. However, primary hyperaldosteronism can also be presented with hypokalemia without hypertension. The differential diagnosis is easy as renin levels are low in Conn syndrome in contrast with others. Our patient had low renin and high aldosterone levels suggesting primary hyperaldosteronism. The pathology revealed adrenal adenoma. The maintenance of normal levels of potassium after surgery supported the diagnosis of Conn syndrome.