RESUMO
Unilateral adrenal hyperplasia is a rare cause of primary hyperaldosteronism (around a 3%) that has surgical treatment. A case of a patient with hypertension resistant to conventional therapy in treatment with 7 drugs who presented with primary hyperaldosteronism due to unilateral adrenal hyperplasia is presented. A left adrenalectomy was performed, and the patient had a good clinical response, with no need of any drug after 2 years of surgery. Unilateral adrenal hyperplasia is a different entity and it is not an asymmetric variant of the bilateral adrenal hyperplasia. In the study of patients with primary hyperaldosteronism and imaging tests with absence of adenoma is a diagnosis that must be considered before cataloguing patients with bilateral adrenal hyperplasia and start a medical treatment, because unilateral adrenal hyperplasia would have a surgical resolution.