Significant Invasion of the Pharyngeal Constrictor Muscle in Early Squamous Cell Carcinoma of the Tonsil.

Objective: To determine whether invasion of the pharyngeal constrictor muscle in early squamous cell carcinoma of the tonsil is correlated with lymph node metastasis. Design: Retrospective analysis of medical records and pathology specimens. Setting: Tertiary care referral center. Patients: Forty-eight patients who were diagnosed as having T2 squamous cell carcinoma of the tonsil and who underwent surgery. They were divided into 2 groups: an invasive group with invasion of the pharyngeal constrictor muscle and a noninvasive group without invasion of the pharyngeal constrictor muscle. Main Outcome Measures: Comparison of regional metastasis, 5-year locoregional recurrence, and 5-year disease- specific survival between the 2 groups. Results: Invasion of the pharyngeal constrictor muscle was found in 36 patients (75%) with T2 squamous cell carcinoma of the tonsil. The rate of lymph node metastasis, the mean (SD) number of positive nodes, and the mean (SD) lymph node density were 81%, 5.47 (9.27), and 0.15 (0.22) in the invasive group, respectively, and 50%, 1.33 (1.72), and 0.04 (0.04) in the noninvasive group, respectively (P=.04, P=.02, and P=.01, respectively). Five-year locoregional recurrence was significantly correlated with invasion of the pharyngeal constrictor muscle (P=.05) and with multiple lymph node metastasis (⩾5 nodes) (P=.04) in the univariate analyses. No factor was correlated with 5-year locoregional recurrence in the multivariate analysis. Five-year diseasespecific survival was significantly correlated with multiple lymph node metastasis (⩾5 nodes) in the univariate analyses (P=.009). Five-year disease-specific survival was not significantly correlated with any clinicopathological factor in the multivariate analysis. Conclusion: Higher risk for multiple lymph node metastasis and 5-year locoregional recurrence seems to be predicted in patients with extratonsillar invasion of the pharyngeal constrictor muscle, even in early squamous cell carcinoma of the tonsil. [ABSTRACT FROM AUTHOR]