Keywords soft tissue;peripheral primitive neuroectodermal tumor;extraosseous Ewing s sarcoma;Askin tumor;clinicopathology;CD99;

• 软组织;外周性原始神经外胚层瘤;骨外尤文氏肉瘤;胸肺区小细胞恶性肿瘤;临床病理;CD99;