Value of neck dissection in patients with squamous cell carcinoma of unknown primary.

Lymph node metastases of cancer of an unknown primary (CUP syndrome) are responsible for 3-5% of the malignant diseases in the head and neck area. More than 70% of these patients show lymph node metastases of an unknown squamous cell carcinoma. The survival depends immediately on number and location of lymph node metastases. For a curative approach modified radical neck dissection combined with postoperative radiation therapy with or without chemotherapy should be considered in N1-N3 lymph node status. A radical neck dissection with postoperative radiation therapy should only be approved in cases of infiltration of the internal jugular vein, the accessory nerve and/or the sternocleidomastoid muscle. The different prognosis of patients with upper cervical and lower cervical lymph nodes should influence the indication and the extent of a neck dissection in the contralateral N0 neck.