Desmoglein 3 is Overexpressed in Inverted Papilloma and Squamous Cell Carcinoma of Sinonasal Cavity

Objectives/Hypothesis: We sought to investigate the role of desmoglein 3 in pathogenesis of sinonasal inverted papilloma (IP) and its malignant transformation. Methods: Fifteen subjects with sinonasal IP and 15 subjects of normal sphenoid sinus mucosa were enrolled. Each specimen was divided into two portions: one for mRNA expression analysis by real-time polymerase chain reaction, and the other for detection of targeted proteins by immunohistochemistry analysis. In addition, another 10 cases of IP with squamous cell carcinoma (SCC) were added for immunohistochemistry analysis. Results: The mRNA expression level of desmoglein 3 was significantly higher in IP tissues than in the normal sinus mucosa (P < .001). In immunohistochemistry study, desmoglein 3 was detected in plasma membrane areas of IP and IP with SCC tissues, but no obvious expression was found in normal sinus mucosa (total score; both P < .001). Positive desmoglein 3 staining was strongly present in nearly all malignant transformation areas of IP with SCC cases (90%), but only in scattered areas of some cases of IP (53%) (total score; P < .001). Conclusions: Desmoglein 3 was overexpressed in IP and IP with SCC, and the overexpression was correlated with malignant transformation of IP. It may provide valuable insight into the pathobiology of this disease, and can potentially provide a venue to predict malignant transformation in sinonasal IP.