Conn Syndrome with Hyperthyroidism and Refractory Hypokalemia: A Case Report

Conn syndrome is an adrenal gland adenoma that causes primary hyperaldosteronism, with a prevalence of <1% in the world population. Therefore, this case report presents a patient with Conn syndrome co-existing with hyperthyroidism. A 26-year-old female was admitted with muscle spasms in the left arm and muscle weakness in both legs for a day, palpitations, excessive sweating, nocturia, polyuria, and polydipsia. The patient had a history of hyperthyroidism for 10 years and routinely took anti-hypertension (Nifedipine), anti-thyroid, and potassium supplements. Physical examination showed the presence of hypertension. In addition, laboratory examinations revealed hypokalemia, slightly elevated FT4. The patient showed a high level of ARR (Aldosterone-Renin ratio; >30 ng/dL), consistent with primary hyperaldosteronism. Since abdominal USG revealed no abnormality, abdominal MRI with contrast was performed and showed an adenoma in the left adrenal gland. During admission, the patient had refractory hypokalemia despite various efforts to correct the defect. An anti-hypertension drug was then administered, particularly a mineralocorticoid antagonist receptor (Spironolactone). After the treatment, the patient had manageable hypertension and a normal potassium serum level, with no symptoms. Subsequently, discharge was then granted after 9 days of treatment, with a surgery schedule. Conn syndrome with hyperthyroidism can cause refractory hypokalemia, which transforms into a challenge in patient management. With early detection and management, the outcome of this case is manageable.