Carcinomas of unknown primary in the head and neck

In approximately 3% to 5.5% of patients presenting with squamous cell carcinoma metastasis to the cervical lymph nodes, the primary source remains elusive despite extensive evaluation and biopsy. The presenting symptom of a unilateral neck mass is initially evaluated with a complete history and physical. This is followed by flexible endoscopy, fine needle aspiration, laboratory and imaging studies and directed biopsies of the upper aerodigestive tract. While the initial attempt fails to locate the primary site, it will eventually become manifest in 20% to 40% of patients. Early identification decreases overall morbidity and mortality. This article summarizes contemporary diagnostic approaches, current imaging techniques, the role of tonsillectomy, and the management and outcomes of carcinoma of unknown primary.