Transoral robotic biopsy of the tongue base: A novel paradigm in the evaluation of unknown primary tumors of the head and neck.

BACKGROUND: Squamous cell carcinoma of the head and neck can present as a cervical metastasis from an unknown primary site. The standard diagnostic workup includes panendoscopy and directed biopsies but this will fail to identify a portion of unknown primary tumors.
METHODS: Herein, we present a case report of a male patient with an unknown primary tumor in which the da Vinci surgical robot was used to evaluate the tongue base.
RESULTS: Clinical evaluation, imaging, and panendoscopy with directed biopsies failed to detect the primary tumor site. Robot-assisted biopsy of a broad area of the tongue base, incorporating submucosal tissue, identified the primary tumor with minimal postoperative morbidity.
CONCLUSION: Failure to localize an unknown primary tumor often results in widespread irradiation of the upper aerodigestive tract, inducing significant morbidity. Robot-assisted biopsies of the tongue base may identify unknown primaries that would otherwise have been missed through standard directed biopsy techniques.