Utility of BerEp4/calretinin and desmin/epithelial membrane antigen (EMA) dual immunocytochemical staining in effusion cytology

Abstract

Background: Pleural mesothelioma (PM) is typically diagnosed late during the disease. Earlier detection can increase the chance of effective therapy.Recurrent pleural effusions are the earliest symptoms displaying an array of cytomorphological changes from reactive atypia to malignancy. Diagnosis is possible on effusion cytology by applying molecular and immunocytochemical markers, the main difficulty being when to suspect PM and to differentiate PM from metastatic adenocarcinoma and reactive mesothelial proliferations. Methods: We evaluated the diagnostic performance of two immunocytochemical dual stains (BerEp4/Calretinin and Desmin/Epithelial Membrane Antigen (EMA)) on 149 ethanol-fixed cytospin preparation as an initial step to solve the mentioned diagnostic difficulty. The immunocytochemical reactivity pattern was evaluated by two independent investigators. The final diagnosis corresponded to PM (n = 20), metastatic adenocarcinoma (n = 83), and mesotheliosis (n = 46) in these cases.Results: Calretinin had 99% specificity and 98% sensitivity for indicating a mesothelial phenotype, while BerEp4 distinguished the adenocarcinoma cases with 98% specificity and 99% sensitivity. EMA displayed 96% specificity and 99% sensitivity in malignant cases, while Desmin without EMA present showed 99% specificity and 96% sensitivity for indicating benign mesothelial proliferation.Conclusions: Interpretation of the four immunoreactions is improved when performed as dual stains. The dual staining is a useful tool in the initial handling of atypical effusions and guides the subsequent choice of antibody panels for more detailed subclassification of malignant effusions.

Comparison of immunohistochemical mesothelial biomarkers in paired biopsies and effusion cytology cell blocks from pleural mesothelioma

“…Dual staining with desmin/EMA may be useful for accurate differentiation between mesothelioma and reactive mesothelial cells. 35 However, focal desmin expression has also been reported in 5%-10% of mesotheliomas in histological specimens, which is why our findings also may represent true expression. 17,36,37 To the best of our knowledge, there are no data for paired histological and cytological specimens in the literature for most of the markers investigated in our study.…”

“…We cannot rule out that the focal desmin positivity in our cytological specimens may represent reactive mesothelium as such cells are very difficult to distinguish from mesothelioma cells. Dual staining with desmin/EMA may be useful for accurate differentiation between mesothelioma and reactive mesothelial cells 35 . However, focal desmin expression has also been reported in 5%–10% of mesotheliomas in histological specimens, which is why our findings also may represent true expression 17,36,37 …”

Diagnostic Utility of Cell block and Immunocytochemistry in Differentiating Malignant from Non-malignant Effusions: A Cross-sectional Study

“…Khurram N et al, also observed in their study that immunostaining with BerEp4 and Calretinin on cell block preparations helped confirm the diagnosis in the majority of suspicious cases [2]. This suggests that BerEp4 is a specific and sensitive marker for adenocarcinoma cells, while Calretinin is a marker of reactive mesothelial cells [16].…”

Malignant mesothelioma tumours: molecular pathogenesis, diagnosis, and therapies accompanying clinical studies

“…Modern Calretinin antibodies need both cytoplasmic and nuclear labeling in order to establish mesothelioma detection. Calretinin has a detection accuracy of 81-100% in edema for mesothelioma ( 69 ).…”