Introduction:
Patients with human papillomavirus (HPV)- positive oropharyngeal squamous cell carcinoma (OPSCC) often present with significant nodal disease burden. Given the increasing incidence and unique nature of HPV-positive OPSCC, further investigation of nodal patterns in this patient population is warranted.

Methods: A retrospective chart review was performed for patients with HPV-positive OPSCC who underwent up-front transoral robotic surgery (TORS) and neck dissection (comprising at least levels II-IV) between October 2016 and September 2021. Demographic and surgical treatment information was obtained for each patient. Histopathology reports were reviewed for lymph node yield as well as the incidence and distribution of LN metastases, particularly to level IV. Local, regional, and distant recurrences were additionally reviewed for all included patients.

Results: 175 patients underwent a unilateral level II-IV neck dissection for OPSCC with an average lymph node yield of 31.4 (±13.4) LNs. 125 patients had histopathological reports that sufficiently commented on the distribution of lymph node metastases. Of this cohort, 50 patients had quantifiable level IV LN counts, with an average level IV nodal yield of 9.1 (± 5.3) LNs. The corresponding rate of pathologic node-positive disease in level IV was 1.6% (2 of 125 patients). Both patients underwent therapeutic NDs and demonstrated evidence of skip metastases (with one patient presenting with only level IV lymphadenopathy; and the other with pathologic LNs in levels II and IV with no evidence of disease in level III). The former patient deferred adjuvant chemoradiation and had evidence of regional recurrence within five months of primary surgical resection. There has been no evidence of local recurrence or distant metastases in either patient to date.

Discussion: Our study highlights the low incidence of level IV LN metastases for HPV-positive OPSCC. Both patients with level IV node-positive disease underwent therapeutic ND and demonstrated evidence of skip metastases. Our findings suggest that HPV-positive OPSCC rarely demonstrates occult metastasis to level IV.