外周原始神经外胚层肿瘤 ,是一组少见的可能起源于中枢和交感神经系统、外周神经的小圆细胞恶性肿瘤。我们遇到 1例 ,现报告如下。患者　女 ,19岁。半年前右胸壁发现一核桃大小肿块 ,无疼痛 ,质硬 ,不活动 ,当时未重视 ,以后发现肿块迅速长大 ,并伴间断性锐痛。查体 :右胸壁见 Peripheral primitive neuroectodermal tumors are a rare group of small-cell malignant tumors that may originate from the central and sympathetic nervous systems and peripheral nerves. We met one case, the report is as follows. Female patient, 19 years old. Half a year ago found a walnut-sized tumor on the chest wall, no pain, hard, inactive, did not pay attention, and later found that the rapid growth of the tumor, accompanied by intermittent sharp pain. Physical examination: see the right chest wall