多发性肌炎是累及骨骼肌的非特异性疾病,与自身免疫关系密切,其病理机制尚不清楚,大多认为是体液免疫反应造成血管壁损害及肌肉改变的主要原因.临床特点为四肢近端肌无力,有时有肌痛和肌萎缩.病理特征表现为肌纤维的坏死、炎性细胞浸润、肌纤维再生及间质血管增多、管壁增厚.曾有作者对多发性肌炎患者进行肌电图、肌肉病理检查和神经活检,发现有神经原性改变、髓纤维髓鞘脱失及轴索变性.本文4例均符合杨荫昌等提出多发性肌炎肯定诊断的标准,做多次不同部位肌肉活检,表现多发性肌炎一般病理改变或神经原性肌萎缩的不同变化,现报告如下.1 临床资料本组共4例,男、女各2例,年龄17～43岁,平均30岁.3例慢性起病,1例急性起病.病程1～24个月,平均12.5个月.既往无毒物接触史.临床表现:4例均有四肢近端肌无力和肌肉萎缩,2例伴关节痛,1例肌肉疼痛和压痛.4例均无皮肤损害及四肢感觉障碍,亦无伴发恶性肿瘤和肯定的胶原-血管疾病.2 Polymyositis is a non-specific disease involving the skeletal muscle, and autoimmunity is closely related to its pathological mechanism is not clear, most of them are considered to be humoral immune response caused by vascular wall damage and muscle changes in the main clinical features of the proximal extremities Weakness, and sometimes muscle pain and muscle atrophy.Pathological features of muscle fiber necrosis, inflammatory cell infiltration, muscle fiber regeneration and interstitial blood vessels, wall thickening.Once the author of myositis patients with EMG, Muscle pathology examination and nerve biopsy found neurogenic changes, myelin sheath demyelination and axonal degeneration.In this paper, four cases are in line with positive yang yinchang put forward positive diagnosis of polymyositis standard, so many different parts of the muscle biopsy, The performance of the common pathological polymyositis or neurogenic muscle atrophy of the different changes, are reported as follows.1 Clinical data of this group a total of 4 cases, 2 males and 2 females, aged 17 to 43 years, mean 30 years .3 Chronic onset, 1 case of acute onset. Duration of 1 ~ 24 months, an average of 12.5 months. Previous non-toxic history of exposure. Clinical manifestations: 4 cases of proximal limb muscle weakness and muscle atrophy, 2 cases with joint pain, 1 case of muscle pain and .4 patients had no pain, skin lesions and limb sensory impairment, nor associated with cancer and certainly collagen - vascular disease .2