Reappraisal of metastatic lymph node topography in head and neck squamous cell carcinomas

Abstract

Objective To analyze the lymphatic distribution of metastatic carcinomatous cells in cervical lymph nodes in head and neck squamous cell carcinoma (HNSCC). Study Design and Setting We retrospectively reviewed 119 patients treated in our hospital for HNSCC (1999-2004). Topography of the neck dissection specimens was prospectively classified according to the classification of Robbins. The 4000 lymph nodes were analyzed by optical microscopy using hematoxylin-eosin-safran (HES) staining. In cases of negative results in level II, cytokeratin (AE1/AE3) immunodetection was performed. Results Metastases were visualized using HES in 6.4% of lymph nodes for oral cavity, and 4.7% of oropharyngeal, 4.4% of hypopharyngeal, and 1.3% of endolaryngeal cancers. The highest incidence of nodal metastasis was observed in level IIa ( P < 0.01). In eight patients (6.7%) with lymph node metastases, level II was spared. In these patients, all 134 nodes histologically negative on HES were confirmed to be negative by IHC. Conclusions Level IIa is the main level involved in regional metastases of HNSCC, regardless of the primary site of cancer. However, in eight (6.7%) patients, level II was spared, as confirmed by IHC. In these cases, level II did not represent the first step of drainage from the tumor. The sentinel lymph node technique in HNSCC is discussed in light of these results.