患者，男，24岁。1991年初因右膝后外侧皮肤“黑色素瘤”在某医院进行病变部位皮肤扩大切除术，切口一期愈合。病理诊断为“恶性黑色素瘤”。术后未进行其它治疗。1995年4月患者感觉右下肢麻木，皮肤感觉减退，并逐渐向上发展至胸背部，同时发现左颈部皮下有一硬性包块，有压痛 Patient, male, 24 years old. In early 1991, due to the “melanoma” of the posterior lateral skin of the right knee, an enlarged skin resection was performed at a hospital site and the incision healed. The pathological diagnosis was “malignant melanoma.” No other treatment was performed after the operation. In April 1995, the patient felt numbness in the right lower extremity, his skin feel diminished, and he gradually developed upwards to the chest and back. At the same time, he found that there was a rigid mass under the left neck and tenderness.