Immunologic detection of occult primary cancer of the head and neck.

Because antibody titers against Epstein-Barr virus (EBV) antigens often are elevated in patients with active undifferentiated and nonkeratinizing nasopharyngeal carcinoma, anti-EBV serologic tests have been applied as a diagnostic aid in patients who have metastatic lymphadenopathy in the neck without an obvious source. IN this study of 44 patients, the serologic testing procedure proved useful in identifying six patients with nasopharyngeal carcinoma that was initially occult but was eventually confirmed by biopsy.