Ultrasound-Guided FNA of Base of Tongue: A Cadaver Study

Abstract

Objective: 1) Determine the utility of ultrasound imaging to visualize the anatomy of the tongue base. 2) Demonstrate that ultrasound imaging can guide transcervical needle placement in the tongue base and thus serve as a surrogate for needle biopsy in the patient with a tongue base lesion.

Method: Design and subjects: Feasibility study of ultrasound-guided needle placement in the tongue base in 37 adult cadavers. Interventions: Ultrasound imaging of tongue base anatomy and guidance of dye injection into the intrinsic muscles. Outcome Measurements: Tongue base anatomy visualization on ultrasound and placement accuracy of dye injection.

Results: Of 37 cadaver heads, 32 were noted to have excellent and identifiable anatomy of the geniohyoid, genioglossus, and intrinsic muscles of the tongue base. The intrinsic muscles were well visualized during methylene blue dye injection on most specimens, with confirmation of the needle tip location and “bloom” of the injection on real-time ultrasound images. After bisection, 25 of 32 (78%) evaluable specimens were found to have accurate placement of dye within the posterior genioglossus and intrinsic tongue base muscles. Neck circumference was similar between those with accurate (mean 37.9 cm) and inaccurate (mean, 37.4 cm) dye placement (P = .75).

Conclusion: This study utilizes a cadaver model to establish that ultrasound visualization of the tongue base provides excellent anatomic detail and demonstrates feasibility of transcervical ultrasound localization of the tongue base for image-guided FNA. This technique has potential applicability to the clinical setting.