Table 1

Immunohistochemical differentiation between ovarian cancer and peritoneal malignant mesothelioma

MarkerpMMOCReferences 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.