Combined use of novel epithelial (MOC-31) and mesothelial (HBME-1) immunohistochemical markers for optimal first line diagnostic distinction between mesothelioma and metastatic carcinoma in pleura.

AIMS: To determine the value of immunohistochemistry in differentiation of malignant pleural mesothelioma from carcinoma in a pleural biopsy we optimized a double panel of MOC-31 and HBME-1 and compared the results with others from the literature. METHODS AND RESULTS: A multi-antibody panel was applied to biopsy samples from 44 cases of malignant pleural mesothelioma and 23 cases of carcinoma metastatic to the pleura. We used monoclonal antibodies against keratins, epithelial membrane antigen (EMA), epithelial antigen Ber-EP4, carcinoembryonic antigen (CEA), tumour-associated glycoprotein (B72.3), LeuM1, vimentin, desmin, epithelial related antigen (MOC-31) and mesothelial cell (HBME-1). Positivity for MOC-31 and Ber-EP4 was found to have the highest nosologic sensitivity (94.1% and 84.6%, respectively) and specificity (86.3% both antibodies) for carcinoma. Positive staining for HBME-1 and vimentin had the highest sensitivity (90.9% and 100%, respectively) and specificity (91.3% and 60%, respectively) for mesothelioma. A two-marker antibody panel with HBME-1 and MOC-31 was the most efficient for the distinction between carcinoma and malignant pleural mesothelioma. CONCLUSION: A combination of MOC-31 (an anti- epithelial marker) and HBME-1 (an anti-mesothelial marker) has a diagnostic efficiency of 76.1% for the distinction between carcinoma and mesothelioma in pleura.