重症肌无力 ( Myasthenia gravis,MG)与多发性肌炎( Polymyositis PM)并存 ,国内外罕见报道。在我们 2 30 0例MG患者中 ,作者发现有 7例与 PM并存 ,现报告如下。1　临床资料两病并存的 7例患者中 ,男 1例 ,女 6例 ,年龄 2 6～ 57岁 ,均有四肢无力、持物和行走困难 ,其中颈项肌 Myasthenia gravis (MG) and polymyositis PM co-exist, rarely reported at home and abroad. In our 3030 patients with MG, the authors found that 7 cases co-exist with PM, are as follows. 1 Clinical data Two patients coexist in two patients, 1 males and 6 females, aged 26 to 57 years old, both limb weakness, holding and walking difficulties, including neck muscle