Squamous cell carcinoma metastatic to the neck from an unknown head and neck primary site

Squamous cell carcinoma metastatic to the neck from an unknown head and neck primary site is relatively uncommon and presents a challenging diagnostic and therapeutic dilemma. Diagnostic evaluation includes fine-needle aspiration of the neck mass, chest roentgenography, computed tomography, and/or magnetic resonance imaging of the head and neck, followed by panendoscopy and biopsies. The primary tumor will be detected in approximately 40% of patients; approximately 80% of cancers are located in the base of the tongue or tonsillar fossa. Management options include treatment of the neck alone or both sides of the neck and the potential head and neck primary sites. The latter approach is associated with better long-term control above the clavicles. The 5-year survival rate is approximately 50% after treatment and is influenced by the extent of neck disease. In this article, we review the pertinent literature.