Level IIb lymph nodes metastasis in elective supraomohyoid neck dissection for oral cavity squamous cell carcinoma: a molecular-based study.

OBJECTIVES: To identify the incidence of level IIb lymph nodes metastasis in elective supraomohyoid neck dissection (SOHND) as a treatment for patients with squamous cell carcinoma (SCC) of the oral cavity.

STUDY DESIGN: Prospective analysis of a case series.

METHODS: Forty-eight patients with SCC of the oral cavity and with no palpable lymph nodes at the neck who underwent an elective SOHND were prospectively studied. The incidence of micrometastasis to level IIb lymph nodes after performing elective SOHND was evaluated by pathologic examination and molecular analysis.

RESULTS: Of the 48 patients, 15 (31%) by pathologic analysis and 22 (46%) by molecular analysis had lymph nodes positive for metastatic SCC. By molecular analysis, 5 (10%) of the 48 patients had involvement of level IIb lymph nodes. All patients with metastasis to level IIb lymph nodes have their primary lesions in the tongue and constituted 22% of patients with tongue lesions. There was no instance of isolated metastasis to level IIb lymph nodes without involvement of other nodes in the SOHND specimens.

CONCLUSIONS: In this study, level IIb lymph node metastasis was only found in association with tongue carcinoma. Although this region may be preserved in elective SOHND in patients with SCC of the oral cavity, it should be included whenever the tongue is the primary site.