ABSTRACT
BACKGROUND: The function of the bcl-2 oncogene was known to prolong cell life by inhibiting apoptosis. PCNA have been used as a cellular proliferation marker. Because there are much similarities between Keratoacanthoma(KA) and Squamous Cell Carcinoma(SCC), it is often hard to differentiate KA and SCC, clinically and histopathologically. Although a number of recent studies have been attempted to separate these two entities by immunohistochemical stains, the distinction between KA and SCC may be still debatable and a matter of speculation. OBJECTIVE: The purpose of this study was to evaluate the usefullness of the method by analyzing immunohistochemical expression of bcl-2 and PCNA in a matter of differentiating KA and SCC. METHOD: 11 cases of Keratoacanthoma and 22 cases of Squamous Cell Carcinoma which are conformed by histopathologic examination were stained with bcl-2 and PCNA immunohistochemically. RESULTS: 1. In KA, The bcl-2 was negative in 100% and the PCNA was positive in 100%. 2. In SCC, The bcl-2 was negative in 95% and the PCNA was positive in 100%. 3. In the pattern of staining of PCNA, KA have more peripheral pattern(73%) than diffuse pattern(27%), otherwise SCC have more diffuse pattern(59%) than peripheral(27%) and focal pattern(14%). CONCLUSION: bcl-2, PCNA, Keratoacanthoma(KA), Squamous Cell Carcinoma(SCC)Our research showed that KA is almost similar to SCC except that there are difference in the pattern of staining of PCNA. According to the result of our study, we think that it is hard to differentiate between KA and SCC only by immunohistochemical staining of PCNA. Althogh immunohistochemical staining of PCNA would not be a confirmative method, it will help us to distinguish KA from SCC as a supplementary measure. By the fact, more researches are necessary to differentiate KA and SCC by immunohistochemical staining.