This study aimed to evaluate the association of a disintegrin and metalloproteinase-33 protein (‘ADAM-33’) expression in vocal polyp formation and to determine its correlation with clinical characteristics.

Medical charts and histological sections of 32 patients diagnosed with vocal polyps who underwent surgery were analysed. Controls were histopathologically normal vocal fold tissues obtained from 36 patients who underwent surgery for laryngeal squamous cell carcinoma. Immunohistochemical staining was performed to detect ADAM-33 expression in epithelial cells, stroma and vessels.

All epithelial, stromal and vascular staining scores were significantly greater in polyp tissue than in controls (p < 0.001). Stromal ADAM-33 staining scores were higher in vocal polyp patients with a symptom duration of less than six months (p < 0.05). Vocal overuse or the presence of reflux symptoms, sinonasal symptoms or allergy did not affect ADAM-33 immunostaining scores (p = 0.05).

In this study, ADAM-33 immunostaining was significantly increased in vocal polyps. Therefore, over-expression of this protein may be associated with vocal polyp pathogenesis.