Evaluation of incidence of metastatic involvement of level IIb subgroup lymph nodes in squamous cell carcinoma of the oral cavity

Abstract

Background: To determine the overall incidence of level IIb lymph node metastases in N0/N+ neck and whether level IIb node removal is necessary in oral squamous cell carcinoma (OSCC) patinets. Material and methods: A prospective analysis of 182 biopsy proven OSCC patients who underwent surgical excision of the primary lesion with safe margins. Based on the site, nodal involvement etc the planned neck dissection has been performed. Resected primary lesion and different levels of removed lymph nodes was marked and sent for histopathological examination. 26 (14.3%) patients underwent bilateral neck dissection and unilateral in remaining 156 patients (85.7%). Results: 22 patients in our study specifically had metastases in level IIb, representing 22 out of 182 patients (12%) and 22 out of 208 neck dissection specimens (10.5%), combining pathologically N0 necks and clinically node-positive necks. 31 patients reported with a local recurrence at 1-year follow-up period, whereas remaining 151 patients had no loco regional residual disease at 1 year follow up. All the patients with recurrent disease were provided palliative treatment. Conclusions: Our results indicate the importance of always dissecting level IIb nodes in case of high metastatic rate of patients with clinically positive neck nodes, exclusively staged as N2b or greater. However, for a therapeutic neck dissection, level IIb clearance should always be done if there are positive lymph nodes at level IIa clinically or intra-operatively on frozen section.