ABSTRACT
Benign laryngeal injuries have been usually differentiated by the clinical finding. Traditionally the pathologic findings between the polyps and nodules by hematoxylin and eosin(H and E) staining looks alike. So we have used immunohistochemical technique to differentiate the laryngeal response to injury. We have studied 25 paraffin embedded tissues(20 cases: vocal polyps, 5 cases: vocal nodules) to compare their distribution of fibronectin and type IV collagen in vocal fold lamina propria by using their monoclonal antibodies. We have chosen fibronectin, a critical structural glycoprotein in the lamina propria, because of its deposition as a result of tissue injury and type IV collagen because of its location only in the basement membrane zone. The results were as follows: 1) In vocal polyps there were sparse fibronectin(less than normal) staining in superficial layer of lamina propria and the type IV collagen staining in basement membrane zone shows thin, normal thickness band form. These suggests that the injury often seems to be confined to the lamina propria only without basement membrane zone disruption. 2) In voal nodules there were intense fibronectin staining(more than normal) in the superficial layer of the lamina propria and the type IV collagen band in basement membrane shows thick and often coupled with disruption injury. The above results represent only two structural proteins, but it may be possible to suggest that the pathogenesis and the development origin of these laryngeal injuries are different. The deposition of fibronectin may explain why some nodules do not respond to voice therapy and suggest the following better treatment.