See also:

• Transoral Robotic Surgery
• Oropharyngeal Cancer, HPV, and Patient Counseling

Created by Sameer A. Alvi, MD and Marisa Buchakjian MD, PhD (submitted 5/13/2022)

Video

Indications

Identification of the primary head and neck squamous cell carcinoma (SCC) after pan-endoscopy w/ biopsies and palatine tonsillectomy do not identify the primary in cases of unknown primary.

Background

With the increase in HPV associated oropharyngeal cancer, more patients present with neck mass as an initial complaint. When the primary cancer cannot be identified after traditional evaluation, tongue base mucosectomy (TBM), also known as lingual tonsillectomy, has been shown to be ~50-70% successful in identifying a small tongue base primary (Hatten 2017, Farooq 2019). This has important implications for treatment refinement for squamous cell carcinoma of the neck with unknown primary. TBM was initially described using a transoral laser microsurgery technique, but with the adoption of transoral robotic surgery (TORS) most centers now utilize this approach.

Contraindications

• Anatomically similar to TORS criteria
• Patients with obvious significant lymphadenopathy burden (multiple nodes, bilateral nodes, radiographic concern for extranodal extension, etc.) who would likely need radiation therapy to the neck anyway may not be good candidates for this procedure.

Procedure

Tongue Base Mucosectomy

1. After exposure of the targeted base of tongue, an incision is made in the mucosa just posterior to the circumvallate papillae. This is deepened until just into the tongue base musculature. This incision can be carried medially towards the midline in a broad plane.
2. An incision is then made in the midline base of tongue and directed posteriorly towards the center of the epiglottis.
3. An incision is then made on the lateral oropharyngeal wall just deep to the mucosa to allow release of the tongue base specimen laterally.
4. Once released laterally, the dissection can proceed anteriorly around the specimen with the goal being to take a superficial sheet of muscle allowing the tongue base mucosal specimen to remain intact.
5. Once the specimen is free off of the tongue, the last remaining attachment is the vallecular mucosa.
6. This incision can be made from anterior, while reflecting the specimen posteriorly towards the epiglottis. Conversely the specimen can also be reflected anteriorly, and the vallecular release incision can be made directly while viewing into the vallecula. Care should be taken to ensure no tongue base mucosa is left behind posteriorly.
7. The assistant should mark the specimen with a clip while still attached to maintain orientation for pathologic analysis after removal from the body.
8. Hemostasis is confirmed and hemostatic agents can be placed into wound at the discretion of the surgeon.
9. Feeding tube placement is also at the discretion of the surgeon.
10. Most patients are able to discharge on POD#1.

References

Hatten KM, O’Malley BW, Bur AM, et al. Transoral Robotic Surgery-Assisted Endoscopy With Primary Site Detection and Treatment in Occult Mucosal Primaries. JAMA Otolaryngol-- Head Neck Surg. 2017;143(3):267-273. doi:10.1001/jamaoto.2016.3419

Farooq S, Khandavilli S, Dretzke J, et al. Transoral tongue base mucosectomy for the identification of the primary site in the work-up of cancers of unknown origin: Systematic review and meta-analysis. Oral Oncol. 2019;91:97-106. doi:10.1016/j.oraloncology.2019.02.018