Is Bilateral Neck Dissection Always Necessary for Hypopharyngeal Squamous Cell Carcinoma? Risk Factors for Occult Contralateral Metastasis.

Abstract

This study aimed to analyze risk factors for occult contralateral lymph node metastasis (LNM) in hypopharyngeal squamous cell carcinoma (HSCC) patients and provide evidence-based recommendations for neck dissection. Retrospective analysis. Tertiary general hospital. We retrospectively analyzed 145 patients with HSCC who underwent primary tumor resection and neck dissection. Clinical and pathological data were collected, including tumor characteristics and lymph node status. Univariate and multivariate logistic regression analyses were conducted to identify risk factors for occult contralateral LNM. The overall occult contralateral LNM rate was 13.24% (n = 18/136). In cN0 patients with Type A & B(unilateral) tumors, occult contralateral LNM occurred in 9.30% (4/43), specifically 12.90% (4/31) for Type A and 0% (0/12) for Type B. In cN+ patients with Type A & B(unilateral) tumors, the rate was 15.05% (14/93), with Type A(unilateral without midline involvement) at 12.5% (9/72) and Type B(unilateral with midline involvement) at 23.81% (5/21). Macroscopic extranodal extension (ENE) in the ipsilateral neck significantly affected contralateral occult metastasis. In contralateral clinically negative necks, occult metastases were primarily concentrated in levels II and III. Central type tumors require bilateral neck dissection. For lateral lesions, contralateral levels II to III are dissected only if ipsilateral cN+, T3-4, or midline crossing is present. Macroscopic ENE in the ipsilateral neck significantly increases the risk of contralateral occult metastasis; intra-operative identification warrants contralateral neck dissection.