Level IIB lymph node metastasis in laryngeal and hypopharyngeal squamous cell carcinoma: single-institution case series and review of the literature.

OBJECTIVES/HYPOTHESIS To determine the incidence of level IIB lymph node metastasis in patients with laryngeal or hypopharyngeal squamous cell carcinoma and to evaluate the need for elective and therapeutic neck dissection of level IIB. STUDY DESIGN Retrospective cohort study and review of the literature. METHODS Patients with laryngeal or hypopharyngeal squamous cell carcinoma (N = 65) were primarily treated with surgery at Mayo Clinic (Rochester, Minnesota) from 2004 through 2010. Neck dissection specimens were analyzed by a pathologist, and metastases to level IIB were reported. In addition, 18 previously published studies, totaling 1,114 neck dissections, were reviewed. RESULTS Level IIB lymph node metastases were present in 4% and 17% of elective and therapeutic neck dissections, respectively. Ipsilateral IIB metastasis was more common than contralateral IIB metastasis in elective and therapeutic neck dissection specimens. Level IIB lymph node metastasis was not significantly associated with level IIA nodal metastasis, level III nodal metastasis, clinical primary tumor stage, clinical nodal stage, or pathologic confirmation of extracapsular spread in either laryngeal or hypopharyngeal squamous cell carcinoma. CONCLUSIONS The rate of occult IIB metastasis in laryngeal and hypopharyngeal squamous cell carcinoma is exceedingly low. In a clinically node-negative case, the ipsilateral and contralateral level IIB nodal packet should not be dissected. For clinically node-positive cases, ipsilateral level IIB dissection should be performed; contralateral IIB dissection should be performed only when indicated.