Interpretation of pleural biopsy specimens and aspirates with the immunoperoxidase technique

Our plain-English summary of Interpretation of pleural biopsy specimens and aspirates with the immunoperoxidase technique, by A. Herbert, P.J. Gallagher (Thorax, 1982).

The study

• Authors: A. Herbert, P.J. Gallagher
• Journal: Thorax
• Published: 1982;37(11):822-7
• Cited by: 16 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

In pleural biopsy specimens and histological sections from the fibrin clots of pleural fluid aspirates it may be difficult to distinguish reactive mesothelial cells from malignant mesothelial cells and metastatic carcinoma. Reactive pleurisy with effusion is usually associated with loss of cohesion and exfoliation of mesothelial cells, which is consistent with the hypothesis that they act as facultative histiocytes. A series of biopsy specimens and sections of clots from benign and malignant pleural effusions have been stained by the immunoperoxidase technique for the histiocytic markers alpha 1-antitrypsin, alpha 1-antichymotrypsin, and lysozyme (muramidase). Eight cases of mesothelioma were included. Mesothelial cells when seen as a monolayer lining the pleural surface were negative. Reactive mesothelial cells, usually seen as exfoliated cells, were consistently strongly positive for alpha 1-antichymotrypsin and more variably for alpha 1-antitrypsin and lysozyme. Malignant cells, whether from carcinoma or from mesothelioma, were usually but not always negative. Consequently immunohistochemical staining for alpha 1-antichymotrypsin is often helpful in distinguishing reactive mesothelial cells from malignant cells.

In plain English

This was a laboratory study of pleural tissue by pathologists at Southampton General Hospital. The authors tested whether staining for three markers of scavenger cells (alpha-1-antitrypsin, alpha-1-antichymotrypsin and lysozyme) could help tell reactive (non-cancerous) mesothelial cells from malignant mesothelioma and metastatic carcinoma. The stained specimens were selected from all surgical pleural specimens received at two Southampton hospitals in 1976. Normal surface lining cells in six cases did not stain. Reactive mesothelial cells stained strongly for alpha-1-antichymotrypsin and more variably for the other two markers. In eight patients with malignant mesothelioma, all sections were negative for lysozyme. Two of eight showed focal staining for alpha-1-antitrypsin and four of eight for alpha-1-antichymotrypsin, but most tumour cells were negative. Carcinoma cells were mostly negative, though in two cases they were strongly positive, and in such cases the method could not separate reactive from malignant cells. The authors concluded that the technique helps identify malignant cells in small specimens. They noted that they lacked a specificity control for the alpha-1-antichymotrypsin antiserum. The article does not discuss 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: Laboratory diagnostic pathology study: immunoperoxidase staining of stored pleural biopsy specimens and pleural fluid clots
• Who was studied: The source series was all surgical pleural specimens received from the Southampton General and Western Hospitals during one year (1976): 95 closed biopsies, 23 open biopsies and pleurectomies, and 158 sections of pleural clots. From this series, the authors stained selected specimens: all 22 closed biopsy specimens with recognisable reactive or neoplastic mesothelium, a selection of open biopsies, 8 fibrin clots from proved reactive pleurisy and 16 from proved malignant effusion. The stained material included 8 patients with malignant mesothelioma.
• Exposure: Not reported. The article does not discuss asbestos or any other exposure. What it tested was staining for alpha-1-antitrypsin, alpha-1-antichymotrypsin and lysozyme.
• Main results:
  • In 6 cases with a single layer of surface lining mesothelial cells, these cells were negative for all three markers.
  • Reactive mesothelial cells (8 cases) stained strongly for alpha-1-antichymotrypsin and more variably for alpha-1-antitrypsin and lysozyme. The same pattern was seen in exfoliated cells in 8 fibrin clots from reactive effusions.
  • In 8 patients with malignant mesothelioma, all sections were negative for lysozyme. Two of eight showed focal staining for alpha-1-antitrypsin and four of eight for alpha-1-antichymotrypsin.
  • In these mesothelioma cases, most tumour cells were negative, and any positive staining was less intense than in reactive exfoliated mesothelial cells.
  • Abnormal mesothelial cells in small biopsies from 3 patients, and exfoliated papillary structures in clots from 2 patients, all later shown to have mesothelioma, were negative.
  • Among 14 clots and 4 biopsies with metastatic carcinoma, the malignant cells were negative in most cases. Carcinoma cells were strongly positive in two cases and weakly positive in one.
  • Where tumour cells stained strongly, the method could not distinguish reactive from malignant cells.
• The authors' conclusion: The authors concluded that alpha-1-antichymotrypsin staining is a reliable way to show reactive cells, being more sensitive than the other two markers. They concluded that the technique helps identify malignant cells in small biopsy specimens and fibrin clots, and that negative staining of neoplastic mesothelial cells is sometimes helpful in diagnosing malignant mesothelioma.
• Limitations the authors state:
  • The authors had no purified blocking antigen to control the specificity of the alpha-1-antichymotrypsin antiserum.
  • Carcinomas of various types can produce these antiproteases, as seen in isolated breast, gastrointestinal and lung metastases in this series.
  • Some small biopsy specimens had no mesothelial tissue left when recut.

Topics

Medical terms in this study, explained in our Lexicon: Pleural Biopsy, Aspirate, Reactive Mesothelial Cells, Mesothelial Cells, Carcinoma, Pleurisy, Biopsy, Pleural Effusion.

Related studies

• Pleural biopsy in the diagnosis of malignant mesothelioma — A. Herbert, P.J. Gallagher (1982)
• Semi-Rigid Thoracoscopic Punch Biopsy Using a Hybrid Knife with a High-Pressure Water Jet for the Diagnosis of Pleural Effusions — Y. Yin, R. Eberhardt, et al. (2016)
• Utility of BRCA1-associated protein 1 immunoperoxidase stain to differentiate benign versus malignant mesothelial proliferations in cytologic specimens — Z. McCroskey, G. Staerkel, et al. (2017)
• Physician-based ultrasound-guided biopsy for diagnosing pleural disease — R.J. Hallifax, J.P. Corcoran, et al. (2014)
• The role of closed pleural needle biopsy in the diagnosis of malignant mesothelioma of the pleura — H.D. Beauchamp, N.K. Kundra, et al. (1992)
• Advantages of thoracic ultrasound-guided fine-needle aspiration biopsy in lung cancer and mesothelioma — M. Sperandeo, L. Dimitri, et al. (2014)

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