总结２７例多发性肌炎和皮肌炎患者皮肤及肌肉组织活检的病理改变。其中多发性肌炎７例，临床上没有皮肤损伤表现，但皮肤活检证实有病理改变。皮肤改变以皮肤鳞状上皮钉脚萎缩，角化过度，纤维结缔组织增生，真皮胶原化或玻璃样变，基底细胞液化为主，肌肉改变以横纹肌纤维粗细不一，横纹肌纤维萎缩断裂，横纹退变或消失为主。 The pathological changes of skin and muscle biopsy in 27 patients with polymyositis and dermatomyositis were summarized. 7 cases of polymyositis, no clinical manifestations of skin damage, but the skin biopsy confirmed the pathological changes. Skin changes to the skin squamous pedestal atrophy, hyperkeratosis, fibrous connective tissue hyperplasia, dermal collagen or glassy change, basal cell liquefaction, muscle changes to the striated muscle fibers vary in size, striated muscle atrophy rupture, stripes Degenerate or disappear.