Functional neck dissection for the clinically negative neck: effectiveness and controversies.

This study was performed to evaluate the effectiveness of functional neck dissection in controlling metastasis to the clinically negative (cN0) neck, focusing on recurrences in the pathologically negative (pN0) neck and the role of extracapsular spread in the cN0 neck. A series of 172 patients (253 dissected fields) treated for cN0 laryngeal or hypopharyngeal cancer with a 5-year minimum follow-up is presented. Occult metastasis was observed in 30% of the patients. Extracapsular spread was present in 39% of the positive nodes. The neck recurrence rate was 5.2%. Surgical specimens from cases of neck recurrence in pN0 necks were reevaluated for micrometastasis by immunostaining with antibody for cytokeratins. The immunohistochemical findings were positive in 1 of 4 cases. Functional neck dissection provides good neck control and survival rates for the cN0 neck. The accurate prognostic significance of extracapsular spread in cN0 necks is still unknown. Micrometastasis alone may be insufficient to explain recurrences in pN0 necks.