The utility of ancillary techniques in effusion cytology

Our plain-English summary of The utility of ancillary techniques in effusion cytology, by K.V. Nance, J.F. Silverman (Diagnostic Cytopathology, 1992).

The study

• Authors: K.V. Nance, J.F. Silverman
• Journal: Diagnostic Cytopathology
• Published: 1992;8(2):185-9
• Type of article: Review
• Cited by: 14 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

We believe that, in general, immunocytochemical studies when used as a panel are the most helpful of the ancillary techniques in the workup of a difficult effusion cytology case. Routine histochemical stains for mucin should also be employed due to their low cost and simplicity, but suffer from lack of sensitivity and specificity. EM examination is especially helpful in the differentiation of metastatic carcinoma from mesothelioma, but lacks specificity due to overlapping ultrastructural features, and is both costly and labor intensive. Immunophenotyping by flow cytometry is useful in the workup of problematic lymphoid proliferations, but DNA analysis by flow cytometry is not useful as a screening technique. Fortunately, most effusion cytology cases will not need the use of ancillary studies, since the diagnosis will be accurately rendered based on the cytomorphologic findings. However, occasional cases will benefit from the use of specific ancillary studies, which can aid in making an accurate, specific, and rapid diagnosis in an otherwise challenging case.

In plain English

This article was a review of laboratory techniques that help pathologists examine effusions (fluid collecting in body cavities). The focus was on difficult cases where reactive mesothelial cells, adenocarcinoma and mesothelioma must be told apart. It reported no new patient study but cited the authors' own earlier studies. The authors described immunocytochemistry (staining with antibodies) as in general the most sensitive and specific technique. They noted that no single antibody consistently separated metastatic carcinoma from malignant mesothelioma. In the authors' recent earlier study, a panel of CEA, EMA, B72.3 and Leu-M1 identified 96% of epithelial malignancies and gave no false-positive diagnoses. Mucin stains were described as lacking sensitivity. Electron microscopy was described as lacking specificity because of overlapping features, and as unable to separate benign from malignant mesothelial cells. The authors judged flow cytometric DNA analysis unsuitable as a screening test, but described flow cytometry immunophenotyping as useful for problem lymphoid cases. The authors concluded that antibody panels were the most helpful extra technique and that most cases would not need extra tests. They also stated that a malignant diagnosis should not rest on positive immunocytochemistry alone.

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 ancillary diagnostic techniques in effusion cytology
• Who was studied: No study population; the review concerned effusion specimens in which reactive mesothelial cells, adenocarcinoma and mesothelioma must be distinguished
• Main results:
  • The authors described immunocytochemistry as, in general, the most sensitive and specific of the ancillary techniques.
  • No single antibody had emerged that consistently distinguished metastatic carcinoma from malignant mesothelioma or from benign mesothelial proliferations.
  • In the authors' recent earlier study, a panel of CEA, EMA, B72.3 and Leu-M1 identified 96% of epithelial malignancies.
  • In that earlier study the panel yielded no false-positive diagnoses.
  • In 12% of confirmed adenocarcinoma cases in that earlier study, the panel identified malignant cells not initially recognized by routine cytology.
  • In the authors' previous studies, EMA stained malignant epithelial cells in 96% (25/26) and 100% (22/22) of carcinomas.
  • In the authors' studies, only 58% (15/26) of adenocarcinomas were labeled by B72.3.
  • In the authors' studies, only 42% (11/26) of adenocarcinomas stained positive for Leu-M1.
  • Routine mucin stains were described as lacking sensitivity, because intracytoplasmic mucin may be present in only 40% to 60% of adenocarcinomas.
  • Electron microscopy was described as lacking specificity because of overlapping ultrastructural features.
  • Electron microscopy was described as unable to separate benign from malignant mesothelial cells.
  • Flow cytometric DNA analysis of effusions was judged not suitable as a screening test, even together with cytology.
  • Immunophenotyping by flow cytometry was described as useful in the workup of problematic lymphoid proliferations.
  • The authors stated that a malignant diagnosis should not be made solely on the basis of positive immunocytochemical studies.
  • The authors stated that most effusion cytology cases would not need ancillary studies.
• The authors' conclusion: The authors concluded that, in general, immunocytochemical studies used as a panel are the most helpful ancillary technique in a difficult effusion cytology case.

Topics

Medical terms in this study, explained in our Lexicon: Cytology, Carcinoma, Mesothelioma.

Related studies

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• Immunocytochemical panel for the identification of malignant cells in serous effusions — K.V. Nance, J.F. Silverman (1991)
• Categorical systems for reporting of cytology specimens: Following the footsteps of Bethesda-like reporting systems — L.J. Layfield, Z. Baloch (2020)
• Positive pleural cytology is an indicator for visceral pleural invasion in metastatic pleural effusions — M.E. Froudarakis, J. Plojoux, et al. (2018)
• Ancillary studies in pleural, pericardial, and peritoneal effusion cytology — K.E. Sundling, E.S. Cibas (2018)
• Utility of BAP1 Immunohistochemistry and p16 (CDKN2A) FISH in the Diagnosis of Malignant Mesothelioma in Effusion Cytology Specimens — H.C. Hwang, B.S. Sheffield, et al. (2016)

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