Updates in Effusion Cytology

Our plain-English summary of Updates in Effusion Cytology, by C.M. Lepus, M. Vivero (Surgical Pathology Clinics, 2018).

The study

• Authors: C.M. Lepus, M. Vivero
• Journal: Surgical Pathology Clinics
• Published: 2018;11(3):523-544
• Type of article: Review
• Cited by: 23 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Effusion cytology plays multiple roles in the management of benign and malignant disease, from primary diagnosis to tissue allocation for ancillary diagnostic studies and biomarker testing of therapeutic targets. This article summarizes recent advances in pleural effusion cytology, with a focus on the practical application of immunohistochemical markers, cytogenetic techniques, flow cytometry, and molecular techniques for the diagnosis and management of primary and secondary neoplasms of the pleura.

Copyright © 2018 Elsevier Inc. All rights reserved.

In plain English

This article was a narrative review of recent advances in effusion cytology, the microscope examination of fluid collecting around the lungs, abdomen or heart (serous effusions). It reported no new patient data but summarized published work on stains, flow cytometry, chromosome tests and genetic tests for these fluids. Citing earlier work, the authors stated that cytology detects malignancy with 40% to 80% sensitivity and that 95% of malignant serous effusions are cancers spread from elsewhere. They reported that malignant mesothelioma presents with effusion in 54% to 89% of patients but causes fewer than 5% of serous effusions. They reported that it is usually associated with occupational asbestos exposure (80% of cases). Effusion cytology had a reported sensitivity of 32% to 53% for mesothelioma, which the authors linked to tissue invasion not being assessable in fluid samples. In studies separating mesothelioma from reactive (benign) mesothelial cells, BAP1 protein loss had up to 67% sensitivity and 100% specificity. Noting that BAP1 loss is rarely seen in carcinomas, the authors considered BAP1 a reasonable first-line diagnostic stain alongside mesothelial lineage markers.

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: Narrative review of published literature (no new data collected)
• Who was studied: Published studies on cytology specimens from serous effusions (pleural, peritoneal and pericardial fluids). The number of studies reviewed and the search method are not stated.
• Exposure: Not an exposure study. In its background on mesothelioma, the review stated that mesothelioma is usually associated with occupational asbestos exposure (80% of cases), with fewer cases attributed to other fibers or therapeutic radiation. No fiber types are named.
• Main results:
  • From the reviewed literature: the sensitivity and specificity of effusion cytology for detecting malignancy ranged from 40% to 80% and from 89% to 98%, respectively.
  • From the reviewed literature: 95% of malignant serous effusions were metastatic disease, mainly adenocarcinomas (70% to 77%).
  • From the reviewed literature: malignant mesothelioma presented with effusion in 54% to 89% of patients.
  • From the reviewed literature: malignant mesothelioma caused fewer than 5% of serous effusions.
  • From the reviewed literature: mesothelioma occurs primarily in men, with a male to female ratio of 4:1 in the pleura and 1.3:1 in the peritoneum.
  • From the reviewed literature: the reported sensitivity of effusion cytology for mesothelioma was 32% to 53%, which is low compared with other malignancies. The authors attributed this to the fact that tissue invasion cannot be assessed in cytologic preparations.
  • From the reviewed literature: the genes CDKN2A, NF2 and BAP1 were altered in 67% to 95%, 50% to 65% and 42% to 80% of mesotheliomas, respectively.
  • From the reviewed literature: loss of BAP1 protein on immunohistochemistry had a sensitivity of up to 67% and a specificity of 100% for mesothelioma across studies. In Table 5, these figures apply to distinguishing mesothelioma from reactive mesothelial proliferations.
  • Table 5, which includes the BAP1 figures, concerns distinguishing reactive from malignant mesothelial proliferations.
  • The authors noted that loss of BAP1 protein expression is rarely seen in carcinomas.
• The authors' conclusion: The authors judged BAP1 immunohistochemistry a reasonable first-line diagnostic stain for mesothelioma, used along with markers of mesothelial lineage.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Pleural plaques and thickening.

Medical terms in this study, explained in our Lexicon: Cytology, Biomarker Testing, Pleural Effusion, Neoplasm, Pleura.

Related studies

• The role of liquid-based cytology and ancillary techniques in pleural and pericardic effusions: an institutional experience — E.D. Rossi, T. Bizzarro, et al. (2015)
• Evaluation of soluble mesothelin-related peptide as a diagnostic marker of malignant pleural mesothelioma effusions: its contribution to cytology — P.A. Canessa, M.C. Franceschini, et al. (2013)
• Comparison of antibodies to HBME-1 and calretinin for the detection of mesothelial cells in effusion cytology — P.A. Fetsch, A. Simsir, et al. (2001)
• Diagnostic mesothelioma biomarkers in effusion cytology — A. Eccher, I. Girolami, et al. (2021)
• Diagnostic value of soluble mesothelin-related peptides in pleural effusion for malignant pleural mesothelioma: An updated meta-analysis — R. Gao, F. Wang, et al. (2019)
• Claudin-4 immunohistochemistry is highly effective in distinguishing adenocarcinoma from malignant mesothelioma in effusion cytology — V.Y. Jo, E.S. Cibas, et al. (2014)

Browse more research in Surgical Pathology Clinics, or return to medical research.