A Systematic Review of Occult Contralateral Neck Metastasis in Tonsillar Squamous Cell Carcinoma

OBJECTIVE: To determine the prevalence of occult contralateral nodal metastasis in tonsillar squamous cell carcinoma (TSCC) in patients who have undergone bilateral neck dissection. DATA SOURCE: A systematic review of English articles identified from PubMed, Embase, and Web of Science databases. REVIEW METHODS: Search terms included "oropharynx," "carcinoma," "lymph node," and "neck dissection." Two reviewers independently screened abstracts, reviewed full texts, and extracted data from all studies that presented the prevalence of contralateral occult nodal metastasis in TSCC. RESULTS: The overall prevalence of occult contralateral nodal metastasis was 10%. The prevalence was 8% for cT1/T2 tumors, 19% for cT3/T4, 1% for N0 in the ipsilateral neck, and 12% for N+. Occult contralateral lymph nodes were most frequently found in neck level II (81%) and level III (19%). No metastatic nodes were found in level I. CONCLUSION: Elective neck dissection of the contralateral neck in TSCC is controversial due the historic morbidity caused by the surgery. A widely accepted recommendation suggests performing an elective neck dissection when the prevalence of occult metastasis is between 15% and 20%. The results of this study suggest that elective contralateral neck dissection will identify occult positivity in 19% of patients with T3/T4 tonsil cancer. In T1/T2 or N0 tumors, the diagnostic yield would be considerably lower at 8% and 1%, respectively. Contralateral nodal sampling could be considered based on patient preference after adequate counseling on the risks/benefits of occult nodal detection. More research is needed on other nodal features to formulate treatment guidelines. Laryngoscope, 135:27-33, 2025.