Expression of Claudin-1, p53 and E-cadherin in pseudoepitheliomatous hyperplasia and squamous cell carcinoma of the head and neck

Background: Pseudoepitheliomatous hyperplasia (PEH) is a reactive proliferation of surface epithelium and can be confused with invasive squamous cell carcinoma (SCC) in head and neck biopsy specimens. To distinguish PEH from invasive SCC, immunohistochemical staining for claudin-1, E-cadherin and p53 was performed. Methods: Eighteen cases of PEH and 29 invasive SCC from head and neck lesions were immunostained and examined. Results: The invasive SCC showed increased staining of claudin-1 (p<0.001) and p53 (p<0.001) and decreased staining of E-cadherin (p=0.005) compared to the PEH specimens. The combined score calculated by adding the positive sum of claudin-1 and p53 and subtracting E-cadherin was useful for the differentiation of SCC from PEH (89.7% sensitivity and 88.9% specificity, p<0.001). Conclusions: The combined immunostaining for claudin-1, p53 and E-cadherin may help differentiate PEH from invasive SCC. The results of this study suggest that the increased expression of claudin-1 and p53 and the decreased expression of E-cadherin maybe markers for the aggressive growth of invasive SCC.