Immunohistochemical differentiation between ovarian cancer and peritoneal malignant mesothelioma
| Marker | pMM | OC | References and comments |
| Wilms' tumor 1 antigen (WT1) | ++ | ++ | Limited use due to poor specificity in determining mesothelial origin83–86 |
| Calretinin | ++ | + | Insufficiently specific65 84–86 |
| Cytokeratin 5/6 | + | + | Limited use; can be focal, patchy, or weak83–85 |
| Mesothelin | + | + | Insufficiently specific65 84 |
| D2-40 | ++ | + | D2-40 will stain epithelioid vascular tumors; it is not a good marker for this differential diagnosis65 83 |
| h-caldesmon | +/− | – | Smooth muscle marker with conflicting studies supporting its use65 83 87 |
| MOC-31/BerEP4 | – | + | May be focally positive in MPM84 85 |
| ER/PR | – | ++ | MPM can have low positive staining (up to 10%)65 88 |
| PAX8 | – | ++ | Some ovarian cancers can have weak staining and weak staining can be seen in a small number of MPM65 66 83 |
MPM, malignant pleural mesothelioma; OC, ovarian cancer; pMM, peritoneal malignant mesothelioma.