The Differential Expression of Lysyl Oxidase in Keratoacanthoma and Squamous Cell Carcinoma / 대한피부과학회지

ABSTRACT

BACKGROUND: Because keratoacanthoma (KA) and squamous cell carcinoma (SCC) are very similar with respect to clinical and histological features but are different with respect to prognosis and treatment, it is necessary to differentiate these two diseases. A number of recent studies have been attempted to differentiate these two diseases using immunohistochemical stains; however, the results obtained using these approaches were inconsistent. OBJECTIVE: The purpose of this study was to examine the expression pattern of polyclonal antibody to lysyl oxidase (LOX) on KA and SCC using an immunohistochemical staining method, and to evaluate the ability of this method in distinguishing these two diseases. METHODS: The expression of LOX in 10 cases of KA and 10 cases of SCC, which were confirmed by histopathologic examination, and 10 cases of normal human skin as a control, were evaluated using an immunohistochemical staining method. We divided the degree of immunohistochemical staining into three classifications --high density, low density, and no density-- based on the level of the expression of LOX in the epidermis and the tumor. Evaluation of the immunohistochemical staining was performed by two dermatologists and one pathologist. RESULTS: The rates of high, low, and no density in KA were 50%, 50%, and 0%, respectively. The rates of high, low, and no density in SCC were 40%, 10%, and 50%, respectively. The rates of high, low, and no density in the control group were 70%, 30%, and 0%, respectively. CONCLUSION: Because the degree of LOX expression in KA and SCC was very diverse, it could not be reliably used as a differential stain for the two diseases. But interestingly, no LOX expression was observed in SCC. This suggests that if expression of LOX is absent, there is a high probability of being diagnosed with a malignant skin tumor rather than a benign skin tumor.