Level IIb lymph node metastasis in elective neck dissection of oropharyngeal squamous cell carcinoma.

This study investigated the oncologic safety of preserving level IIb lymph nodes in ipsilateral and/or contralateral elective neck dissection (END) in patients with oropharyngeal squamous cell carcinoma (SCC). Fifty-one oropharyngeal SCC patients who underwent surgery as an initial treatment were reviewed. Twenty-one patients had clinically node negative necks (cN0) while 30 patients had ipsilateral clinically node positive necks (cN+). Of the cN0 patients, bilateral or ipsilateral END was performed in 15 and six patients, respectively. For the cN+ cases, ipsilateral therapeutic neck dissection with contralateral END was performed in 24 of 30 patients. In the cN0 patients, nodal metastasis to level IIb lymph nodes was not observed in any ipsilateral (21) or contralateral necks (15). Of the 24 cN+ patients who underwent contralateral END, two cases (8.3%) showed contralateral occult level IIb lymph node metastasis. Our data suggest that in cN0 oropharyngeal cancer patients, level IIb lymph nodes may be preserved in ipsilateral and contralateral neck dissection. However, caution is advised when preserving contralateral level IIb nodes in ipsilateral cN+ cases.