how useful are the “newer” markers in body fluid cytology?
CONTEXT: Differentiating reactive effusion, malignant mesothelioma, and metastatic adenocarcinoma in body cavity fluids can be challenging. Interpreting immunohistochemical markers in cell block preparations can be difficult because of nonspecific staining, focal staining, or poor staining quality. We selected a panel of conventional and newer markers to assess their utility in evaluating effusions. OBJECTIVE: To evaluate the efficacy of 5 immunohistochemical markers in the differential diagnosis of reactive mesothelial proliferation, malignant mesothelioma, and metastatic adenocarcinoma in body cavity fluids. DESIGN: A total of 72 formalin-fixed, paraffin-embedded cell block specimens from pleural and peritoneal effusions, including 5 mesotheliomas, 48 adenocarcinomas, and 19 benign effusions were stained with antibodies against calretinin, D2-40, XIAP, MOC-31, and WT1. RESULTS: All benign effusions and mesotheliomas demonstrated diffuse membranous staining with D2-40. All mesotheliom