TY - JOUR T1 - Primary Aldosteronism Simulating Polymyositis JF - The Journal of Rheumatology JO - J Rheumatol SP - 1529 LP - 1533 DO - 10.3899/jrheum.110034 VL - 38 IS - 7 AU - YAN-CHUN TANG AU - SHAO-KUN WANG AU - WEI-LING YUAN Y1 - 2011/07/01 UR - http://www.jrheum.org/content/38/7/1529.abstract N2 - To the Editor:Primary aldosteronism (PA) is a condition in which tumors or hyperplasia of the zona glomerulosa of adrenal cortex cause overproduction of aldosterone and suppression of renin activity, resulting in refractory hypertension, hypokalemic paralysis, and potassium-losing nephropathy. Most patients present with typical features and are easily diagnosed. However, some patients may have special presentations and represent a major challenge for diagnosis and treatment. For example, patients with PA prominently characterized by hypokalemic myopathy (HM) may resemble patients with polymyositis (PM) clinically and pathologically.We describe 3 cases of PA who presented to our hospital with HM as a prominent feature of their hyperaldosteronism. Findings in these patients included muscle pain and weakness, significantly increased creatine kinase (CK), myopathic changes on electromyography (EMG), or inflammatory cell infiltration on muscle biopsy. Early diagnosis and treatment for these patients were delayed because of the PM-like findings. The clinical and enzymatic features of muscle involvement and the electromyographic and/or histological findings of muscles were substantially consistent with the diagnosis of PM1.Few cases of PA chiefly characterized by HM have been reported. A search of reports published in China over the past decade identified 7 cases2,3,4,5,6,7. In order to increase clinicians’ awareness and understanding of PA simulating PM and prevent possible misdiagnosis, we analyzed 3 cases admitted to our institution and 7 treated by others. A 45-year-old previously healthy man presented to our outpatient department with muscle myalgia and weakness involving all extremities for 10 days. Serum CK was 18,561 IU/l and EMG confirmed myogenic damage. He was admitted for suspected PM. Blood pressure (BP) was 185/115 mm Hg. He had a passive position. No rash was observed and thyroid gland was not enlarged. Examination of heart, lung, … Address correspondence to Dr. Tang; E-mail: yt.lyls{at}163.com ER -