The potential risk of vessel infiltration and cervical lymph node metastasis in hypopharyngeal superficial squamous cell carcinoma: a retrospective observational study

Conclusion: The depth of hypopharyngeal superficial cancer may predict vessel infiltration and potential risk of cervical lymph node metastasis. Objectives: To elucidate the histopathological predictors of vessel infiltration and the risk of regional lymph node metastasis in hypopharyngeal superficial cancer. Methods: This study included 31 lesions from 30 patients who had undergone transoral en bloc resection in the hospital. Patients with intraepithelial neoplasia or muscular invasion were excluded. Patient characteristics, nodal status, state of vessel infiltration, state of perineural invasion, histopathological parameters, and post-operative cervical lymph node recurrence were retrospectively examined. The histopathological parameters measured were tumor diameter and the following three parameters: tumor thickness, depth from the mucosal surface, and depth from the basement membrane. Correlations between histopathological parameters and state of vessel infiltration were statistically analyzed. Results: Of the 31 lesions examined, four had vessel infiltration. Three of the four lesions with vessel infiltration had regional lymph node metastasis as well as subsequent lymph node metastasis. Lesions with vessel infiltration were significantly deeper than those without. In contrast, there was no significant difference in lesion diameters. In addition, there was no correlation between the depth and the diameter of the lesion.