A case of Addison's disease associated with the Lambert-Eaton myasthenic syndrome.

Nonneoplastic Lambert-Eaton Myasthenic Syndrome (LEMS) is rare. A 27-year-old man as initially having the diagnosis of Addison's disease was admitted to the hospital because of fatigue, dry-mouthness and proximal limb weakness for 1 year. A diagnosis of LEMS was made from electrophysiological studies. Clinical and laboratory studies revealed no malignancy. We report the first case of Addison's disease associated with non-neoplastic LEMS. It is possible that subclinical LEMS might be present in patients with Addison's disease more frequently than currently believed, since the prominent symptoms of LEMS may be confused with symptoms of Addison's disease.