原发灶不明的颈部淋巴结转移性鳞癌占头颈部恶性肿瘤的4％～5％。原发灶不明的原因一方面是原发肿瘤可自行消退,另一方面原因是当前的检查、诊断设备技术尚不能发现这些患者的原发灶。作者对McGill大学医院在1978年～1991年间接治的54例原发灶不明的颈部淋巴结转移性鳞癌(52例)、淋巴上皮瘤(1例)和未分化癌(1例)进行了回顾性分析。按照头颈肿瘤的AJCC分期,N_1期5例,N_(2a)、 Undiagnosed metastatic squamous cell carcinoma of the cervical lymph node accounts for 4% to 5% of head and neck malignancies. The reason for the unknown origin of the primary tumor is that the primary tumor can subside on its own. On the other hand, the current examination and diagnostic equipment technology cannot detect the primary tumor in these patients. The authors performed 54 cases of cervical lymph node metastatic squamous cell carcinoma (52 cases), lymphoepithelial neoplasia (1 case), and undifferentiated carcinoma (1 case) whose primary tumors were indirectly treated at McGill University Hospital from 1978 to 1991. Retrospective analysis. According to the AJCC stage of head and neck neoplasms, there were 5 N1 stages, N_(2a),