Hyoid bone involvement by squamous cell carcinoma: clinical and pathological features

The incidence of hyoid bone involvement by neoplasia is undetermined, despite its importance in hyoid-preserving surgery. Eleven (1.46%) of 755 whole-organ laryngeal specimens examined demonstrated hyoid bone infiltration. These included 6 cases originating from the larynx, 3 from the vallecula, and 1 case each from the pyriform fossa and tongue base. Clinically, vallecular involvement was helpful in determining hyoid invasion; however, computed tomography (CT) was disappointing. The greater cornu was the sole site of invasion in six cases. Ten of 11 cases were secondary to direct tumor spread. All carcinomas were advanced, with variable differentiation. Vascular and neural invasion was a prominent feature. Hyoid bone invasion is rare, and associated with a poor prognosis. Hyoid bone preservation is feasible in a majority of patients.