Diagnosis and management of squamous cell carcinoma of unknown primary tumor site of the neck.

The development of metastatic carcinoma in cervical lymph nodes is a relatively common syndrome. In most patients, meticulous evaluation of the head and neck area and the lungs will identify a primary tumor site. FNA biopsy of the cervical lymph nodes is the recommended initial biopsy technique; open biopsy should be withheld until after a search for the head and neck primary tumor site is completed. In the patient with no identified primary tumor site, prognosis depends on the site and extent of neck involvement. Because comparative trials have not been performed, conclusions regarding optimal therapy must be made by inference from existing data. Patients with N1 disease located in the upper or midcervical lymph nodes have a relatively high cure rate and can usually be treated with a single local treatment modality (radiation therapy or radical neck dissection). Patients with N2 or N3 disease are probably best treated with combined local modalities including surgical resection followed by radiation therapy. Most investigators have recommended high-dose radiation therapy as is used to treat squamous cancer of the head and neck, with inclusion of those areas in the head and neck that may harbor an occult primary tumor site. Limited data exists regarding the benefit of systemic therapy added to local therapy in these patients. However, treatment with cisplatin and fluorouracil before definitive local therapy is reasonable in patients with N3 disease, who have very poor prognoses with local modalities alone.