Incidence of level IIB lymph node metastasis in supraglottic laryngeal squamous cell carcinoma with clinically negative neck--a prospective study.

BACKGROUND The purpose of this study was to determine the incidence of level IIB metastasis in patients with clinically negative (N0) necks with squamous cell carcinoma (SCC) of the supraglottic larynx and to assess whether level IIB lymph nodes may be left undissected in such patients. This was a prospective analysis of a case series. METHODS A prospective analysis of 68 patients with SCC of the supraglottic larynx and N0 neck who underwent surgical treatment of the primary lesion with simultaneous selective neck dissection (SND) of levels II and III. During neck dissection, level IIB lymph nodes were separately removed and processed. Occult metastasis at levels IIA, IIB, and III and the regional recurrence within this area were evaluated. RESULTS One hundred twenty-two SND (levels II and III) procedures were performed on 68 patients in this series. The occult metastasis rate was 30.9% (21 of 68). The mean number of lymph nodes harvested in level IIB was 4.1 (range, 1-14). In none of the 122 SND specimens (levels II and III) was metastasis found in level IIB either in the ipsilateral or contralateral neck sides. Five patients developed neck recurrence, none of which was in level IIB. CONCLUSION When SND was carried out for patients with SCC of the supraglottic larynx with N0 neck, superselective neck dissection removing lymph nodes in levels IIA and III was adequate. Level IIB lymph node pads may be left undissected so that spinal accessory nerve dysfunction is decreased and operative time reduced.