[Immunohistochemistry in the differential diagnosis of mesothelioma and adenocarcinoma. Evaluation of 5 new antibodies and 6 traditional antibodies].

The aim of this study was to evaluate three recently marketed putative mesothelioma-binding antibodies, calretinin, HBME-1 and thrombomodulin, and two putative adenocarcinoma-binding antibodies, AUA1 and MOC31, on paraffin sections from 28 mesotheliomas and 30 adenocarcinomas. Moreover, the expression of ACE, BerEP4, CA125, CA19.9, LeuM1 and vimentin was assessed. Calretinin, HBME-1 and thrombomodulin, which showed a 100%, 89% and 43% sensitivity, and a 50%, 70% and 87% specificity for mesothelioma respectively, were less efficient than vimentin (100% specificity and 67% sensitivity) for the positive identification of mesothelioma. AUA1, BerEP4 and MOC31 were 100% sensitive to adenocarcinoma, with BerEP4 and MOC31 having the highest specificity (86% each). The immunophenotype "vimentin-positive, ACE-negative, CA19.9-negative" yielded 100% sensitivity and 97% specificity for diagnosis of mesothelioma. We advocate the use of the four-marker panel of ACE, CA19.9, MOC31 (or BerEP4) and vimentin for differentiating mesothelioma from adenocarcinoma.