[Primary hyperaldosteronism without arterial hypertension].

Treatment-resistant hypokalaemia (2.27 mmol/l) developed in a 43-year-old woman. Plasma renin activity was depressed (0.24 ng/ml.h), aldosterone and hydroxycorticosterone concentrations were elevated (123 ng/dl and 688 ng/dl, respectively). Mean blood pressure value (30 readings) was 133/88 mm Hg. An adrenal adenoma was diagnosed by ultrasound, computed tomography and subtraction angiography and then removed. Postoperatively the signs of hyperaldosteronism (Conn's syndrome) regressed and the average blood pressure was 112/76 mm Hg. Blood-gas analysis, which preoperatively had shown a minimal metabolic alkalosis, now revealed a mild metabolic acidosis. Preoperatively present bilateral renal calcifications in the region of the papillary tips were confirmed by computed tomography. An acid loading test revealed diminished renal acid secretion, making the diagnosis of distal renal-tubular acidosis. The latter, in combination with the primary hyperaldosteronism, may have been the cause of the low blood pressure, unusual in Conn's syndrome.