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

Our plain-English summary of Utility of BerEp4/calretinin and desmin/epithelial membrane antigen (EMA) dual immunocytochemical staining in effusion cytology, by A. Hjerpe, E. Demir, S. Abd-Own, et al (Cancer Medicine, 2023).

The study

• Authors: A. Hjerpe, E. Demir, S. Abd-Own, K. Dobra
• Journal: Cancer Medicine
• Published: 2023;12(5):5334-5340
• Cited by: 8 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

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.

© 2022 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

In plain English

This study, from Karolinska University Hospital Huddinge in Stockholm, Sweden, tested two paired ("dual") laboratory stains on fluid drained from the chest (effusions). The aim was to tell pleural mesothelioma apart from metastatic adenocarcinoma and from benign reactive changes, called mesotheliosis. The authors re-examined 149 archived samples that had been stained in routine care between January 2019 and June 2020. These were 20 pleural mesotheliomas, 83 adenocarcinomas and 46 mesotheliosis cases, meaning no sign of cancer within one year. Two observers judged the slides blindly. Calretinin without BerEp4 identified mesothelial cells with 98% sensitivity and 99% specificity. BerEp4 stained 82 of 83 carcinoma samples, none of the 20 mesotheliomas and 1 of 46 mesotheliosis samples. EMA appeared in 102 of 103 malignant samples and in 2 of 46 benign ones. Desmin without EMA appeared in 44 of 46 mesotheliosis samples and in 1 of 103 malignant ones. The authors concluded that the dual stains are useful as a first step to guide further testing, but that in most malignant cases they are not enough for a final diagnosis. The study did not examine asbestos exposure.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Diagnostic accuracy study: archived effusion slides, stained in clinical routine, were re-evaluated blindly by two observers. Sensitivity, specificity, and positive and negative predictive values were calculated.
• Who was studied: 149 effusion samples from the archives of the Laboratory for Clinical Cytology and Pathology, Karolinska University Hospital Huddinge, Stockholm, Sweden, stained between January 1, 2019 and June 30, 2020. The final diagnoses were 83 adenocarcinomas, 20 (pleural) mesotheliomas and 46 reactive mesothelial proliferation (mesotheliosis) cases, defined as no sign of cancer within 1 year after thoracocentesis. Three cases without a definite diagnosis were excluded.
• Exposure: No asbestos exposure was studied. What was tested was two dual immunocytochemical stains, BerEp4 with calretinin and desmin with epithelial membrane antigen (EMA), performed on ethanol-fixed cytospin preparations of effusions.
• Main results:
  • Calretinin reactivity without BerEp4 was seen in 20/20 pleural mesotheliomas, 45/46 mesotheliosis cases and 1/83 carcinomas. Its sensitivity for a mesothelial phenotype was 65/66 (98%) and its specificity 82/83 (99%).
  • BerEp4 reactivity was seen in 82/83 carcinomas (99%), 0/20 pleural mesotheliomas and 1/46 mesotheliosis cases. For indicating carcinoma, sensitivity was 99%, specificity 98% and positive predictive value 99%.
  • EMA reactivity was seen in 19/20 pleural mesotheliomas, 83/83 carcinomas and 2/46 mesotheliosis cases. For indicating malignancy, sensitivity was 102/103 (99%), specificity 44/46 (96%) and positive predictive value 102/104 (98%).
  • Desmin reactivity without EMA was seen in 44/46 mesotheliosis cases (96%), 1/20 pleural mesotheliomas and 0/83 carcinomas. For indicating benign mesothelium, specificity was 102/103 (99%) and positive predictive value 44/45 (98%).
  • One effusion had malignant cells reactive to both calretinin and EMA, with BerEp4 and desmin negative. Further follow-up excluded pleural mesothelioma, and the final diagnosis was carcinosarcoma.
• The authors' conclusion: The authors concluded that the four markers, used as dual stains, are useful in effusion cytology for diagnosing pleural mesothelioma and distinguishing it from carcinoma and reactive mesotheliosis. They added that the stains are best used as an initial step to guide further diagnostic tests.
• Limitations the authors state:
  • The authors state that in most malignant cases the two dual stains are not sufficient for a final diagnosis.
  • The authors state it remains unshown whether BAP1 can replace desmin when paraffin-embedded cell blocks are used.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Calretinin, Desmin, Epithelial Membrane Antigen (EMA), Cytology, Pleural Mesothelioma, Pleural Effusion, Adenocarcinoma.

Related studies

• The diagnostic utility of D2-40, calretinin, CK5/6, desmin and MOC-31 in the differentiation of mesothelioma from adenocarcinoma in pleural effusion cytology — T.S. Hyun, M. Barnes, et al. (2012)
• The distinction of adenocarcinoma from malignant mesothelioma in cell blocks of effusions: the role of routine mucin histochemistry and immunohistochemical assessment of carcinoembryonic antigen, keratin proteins, epithelial membrane antigen, and milk fat globule-derived antigen — E.S. Cibas, J.M. Corson, et al. (1987)
• Changing clinical course of patients with malignant mesothelioma: implications for FNA cytology and utility of immunocytochemical staining — G.H. Yu, L. Soma, et al. (2001)
• Practical utility of insulin-like growth factor II mRNA-binding protein 3, glucose transporter 1, and epithelial membrane antigen for distinguishing malignant mesotheliomas from benign mesothelial proliferations — S. Chang, M.H. Oh, et al. (2014)
• IMP3/L523S, a novel immunocytochemical marker that distinguishes benign and malignant cells: the expression profiles of IMP3/L523S in effusion cytology — K. Ikeda, G. Tate, et al. (2010)
• Immunocytochemical utility of claudin-4 versus those of Ber-EP4 and MOC-31 in effusion cytology — T. Oda, S. Ogata, et al. (2016)

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