[A case of elderly-onset sarcoid myopathy with features resembling polymyositis]

A 75-year-old woman was admitted with a history of acute muscle weakness of her legs for two weeks. Physical examination showed no abnormal findings. Neurological examination revealed symmetrical proximal muscle weakness of legs with muscle pain on grasping. Laboratory data showed normal serum creatine kinase level and marked increases in the levels of serum ACE and soluble interleukin 2. Electromyography showed no myopathic changes. MRI T2 weighted imaging (T2WI) imaging for femoral skeletal muscle demonstrated scattered high and low intensity signals. Muscle biopsy from the right rectus femoris muscle showed granuloma with giant cells of Langhans. She was given a diagnosis of sarcoid myopathy, and motor weakness and abnormal intensity signals on T2WI in this patient were dramatically improved with oral administration of prednisolone (40 mg/day).