Markers used to differentiate carcinoma from mesothelioma showed immunoreactivity in peritoneal mesothelioma: estrogen receptor (2 of 84; 2%), B72.3 (6 of 196; 3%), CK20 (5 of 116; 4%), CD15 (7 of 192; 4%), p63 (3 of 62; 5%), carcinoembryonic antigen (9 of 199; 5%), PAX8 (12 of 191; 6%), progesterone receptor (5 of 71; 7%), Ber-EP4 (17 of 209; 8%), and CD138 (9 of 91; 10%).
The diagnostic utility of PAX8 immunostaining of malignant peritoneal mesothelioma presenting as serous ovarian carcinoma: A single-center report of two cases.
These data show that PAX8 is expressed in both benign and malignant mesothelium, and that BAP1 loss is highly specific for MPM, in the differential with both benign mesothelial proliferations and OTSs.