Severe hypothyroidism masquerading as renal impairment.

A case of severe hypothyroidism in a 51-year old male is presented. The patient was especially complaining of weakness, stiffness and moderate pain in the proximal muscle groups together with rhinorrhea and nasal stenosis. Because of severely elevated S-creatine-kinase combined with reduced creatinine clearance and proteinuria, polymyositis with secondary glomerulopathy was suspected. Meanwhile, biopsies from skin, muscle, and kidney were normal. All symptoms disappeared 3 months after thyroid replacement therapy was initiated. S-TSH should be considered when evaluating patients with renal impairment of unknown etiology.