E-cadherin and calretinin: a useful combination of immunochemical markers for differentiation between mesothelioma and metastatic adenocarcinoma.

To assess the diagnostic accuracy of combinations of antibodies in the differential diagnosis of metastatic carcinomas and mesotheliomas in pleural lesions. The specificity and sensitivity of the commercially available antibodies Ber-EP4, MOC-31, CEA, B72.3, CD15, E-cadherin and calretinin were evaluated using an indirect immunoperoxidase staining technique. This technique was applied to formalin-fixed, paraffin-embedded tissue blocks of pleural lesions. Twenty-one patients with metastatic carcinoma (MC) and 20 patients with malignant mesothelioma (MM) were included. The combination E-cadherin/calretinin had the highest specificity (MC 100% and MM 91%) and sensitivity (MM 100% and MC 91%) considering both categories of tumours. The combination of E-cadherin/calretinin appears to be a suitable panel for distinguishing metastatic carcinomas and mesotheliomas in pleural lesions. The additional value of other markers is limited.