AIM: To evaluate by histological and immunohistochemical methods the epithelial lesions in vocal nodule and correlate with polyp, laryngeal edema and vocal folds without macroscopic lesions. STUDY DESIGN: Chart review. MATERIAL AND METHOD: In a retrospective analysis of medical records, twenty-six patients, who underwent microsurgical excision of laryngeal inflammatory lesions (nodules, polyps and laryngeal edema), were identified. Vocal folds without macroscopic lesions were obtained from autopsy. To evaluate epithelial lesions, specimens were stained with H&E, PAS, and with antibodies against laminin and collagen type IV. These specimens were analyzed by light microscopy. RESULTS: Lesions diagnosed as nodules showed more collagen type IV and laminin deposition when compared to polyps (p=0,034 and p=0,036, respectively) and to vocal folds without macroscopic lesions (p=0,019 and p=0,021, respectively). Nodules showed basement membranes thicker than polyps on PAS stain (p=0,102). Laryngeal edema could not be differentiated from nodules, polyps or vocal folds without macroscopic lesions by PAS, laminin or collagen type IV stain (p>0,10). CONCLUSION: By histological and immunohistochemical techniques to evaluate epithelium of laryngeal inflammatory lesions we conclude that vocal fold nodule differentiate from polyps on the three techniques used to stain basement membrane (PAS, laminin, collagen IV) and from vocal folds without macroscopic lesions on two techniques used (laminin, collagen IV). Laryngeal edema cannot be differentiated from the others laryngeal lesions, neither from vocal folds without macroscopic lesions, when the techniques before described are used.
vocal fold; basement membrane; immunohistochemistry
