The role of insulin-like growth factor-II mRNA-binding protein 3,cyclooxygenase-2, and galectin-3 in differentiating malignant melanoma from benign melanocytic lesion: immunohistochemical study

Background: Melanoma is a malignancy arising from melanocytes. Wide ranges of melanomaassociated antigens have been identified for which immunohistochemical reagents have been developed. Insulin-like growth factor-II mRNA-binding protein 3 (IMP-3), cyclooxygenase-2 (COX-2), and galectin-3 showed variable expressions in different lesions and could give better diagnosis of malignant tumors when combined together. Objective: To evaluate the role of immunohistochemistry using IMP-3, COX-2, and galectin-3 in differentiating malignant melanoma from benign melanocytic lesions. Materials and methods: The study was carried out on 28 selected archival cases (16 benign melanocytic lesions and 12 malignant melanomas). Paraffin sections of 4–5 μm thickness were stained with H E to confirm their histological diagnosis and with IMP-3, COX-2, and galectin 3 for immunohistochemical evaluation. Results: Comparison between immunohistochemical expressions of IMP-3, COX-2, and galectin-3 in different lesions revealed significant difference between benign melanocytic lesions and malignant melanoma. However, immunohistochemical expression of both IMP-3 and galectin-3 showed high statistical difference between malignant melanoma and benign melanocytic lesions. Conclusion: These findings indicate that the combined use of both IMP-3 and galectin-3 has a diagnostic value in segregating nevi from malignant melanoma.