An enlarged cervical lymph node is often the first clinical manifestation of a neoplastic process in the head and neck. Cervical lymph node metastasis is the presenting symptom in 25% of patients with cancer of the oral cavity and oropharynx, 47% of patients with cancer of the nasopharynx, and 23% of patients with thyroid cancer (1,2). In some instances, however, despite a thorough search, a primary tumor cannot be found, and these cases are called carcinoma of unknown primary (CUP). It is difficult to precisely evaluate the frequency of these cervical CUPs relative to the total number of tumors of the upper respiratory and digestive tract. In several large series (Table 1), this frequency varied between 2.6% and 6%, with an average of about 3.7% (3-7).