Ultrasound-Guided Fine-Needle Aspiration of the Tongue Base: A Cadaver Feasibility Study

Objective. The authors hypothesize that floor-of-mouth and tongue base anatomy can be visualized with ultrasound and that ultrasound can be used to accurately guide needle placement and dye injection into the tongue base, serving as a surrogate for fine-needle aspiration. Study Design. Observation of experimental intervention. Setting. Medical school cadaver anatomy laboratory. Subjects and Methods. Ultrasound imaging was performed on human cadaveric specimens to visualize the anatomy of the floor of mouth and base of tongue in a midline transcervical approach. Methylene blue dye was injected under ultrasound guidance into the base of tongue. Specimens were dissected, and results were counted and analyzed. Results. Twenty-five of 32 (78%) cadaver specimens were found to have correct placement of dye within the posterior genioglossus and intrinsic tongue musculature. Seven cadavers did not have correct placement of dye. Of these, 3 had dye staining the walls of the oropharynx and epiglottis. Two specimens had dye injected erroneously into the geniohyoid muscles. One patient was found to have had a partial glossectomy. Difference in neck circumference was not significant between those with correct (mean, 37.9 cm) and incorrect (mean, 37.4 cm) dye placement (P = .75). Conclusion. Anatomy of the floor of mouth and tongue base can be readily depicted with ultrasonography. After reasonable success of injecting dye into cadaver tongue bases, the authors conclude that there appears to be a future clinical role for ultrasound-guided fine-needle aspiration of the tongue base for tongue base lesions.