Differentiation of mesothelioma and adenocarcinoma: immunoreactivity of eleven markers, including five novel antibodies

The aim of this study was to evaluate three recently marketed putative meso thelioma-binding antibodies, calretinin, HBME-1 and thrombomodulin, and two putative adenocarcinoma-binding antibodies, AUA1 and MOC31, on paraffin se ctions from 28 mesotheliomas and 30 adenocarcinomas. Moreover the expressio n of ACE, BerEP4 CA125, CA19.9, LeuM1 and vimentin was assessed. Calretinin , HBME-1 and thrombomodulin, which showed a 100 %, 89 % and 43 % sensitivit y, and a 50 %, 70 % and 87 % specificity for mesothelioma respectively, wer e less efficient than vimentin (100 % specificity and 67 % sensitivity) for the positive identification of mesothelioma. AUA1, BerEP4 and MOC31 were 1 00 % sensitive to adenocarcinoma, with BerEP4 and MOC31 having the highest specificity (86 % each). The immunophenotype << vimentin-positive, ACE-nega tive, 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 (oi BerEP4) and vimentin for differentiating mesothelio ma from adenocarcinoma.