The diagnostic utility of maspin in the distinction between malignant mesothelioma and pulmonary adenocarcinoma

Our plain-English summary of The diagnostic utility of maspin in the distinction between malignant mesothelioma and pulmonary adenocarcinoma, by E.U. Akyildiz, B. Oz, I. Sehitoglu, et al (The Journal of International Medical Research, 2010).

The study

• Authors: E.U. Akyildiz, B. Oz, I. Sehitoglu, H. Demir
• Journal: The Journal of International Medical Research
• Published: 2010;38(3):1070-6
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Immunohistochemistry is frequently employed to differentiate between malignant mesothelioma (MM) and pulmonary adenocarcinoma (AC) infiltrating the pleura, but there is uncertainty as to which antibodies are most useful. The present study investigated the presence of the serine protease, maspin, in epithelioid MMs and evaluated the diagnostic utility of maspin for the differential diagnosis between epithelioid MM and pulmonary AC with pleural involvement. The results showed more frequent maspin immunostaining among AC cases compared with MM cases. Maspin positivity was significantly higher among AC cases with respect to both the extent and intensity of staining. A significant difference also existed between the two tumour types with respect to the overall maspin score. Despite these findings, the sensitivity and specificity of maspin positivity to detect AC were only 59% and 73%, respectively, indicating that detection of maspin is of no value for the differential diagnosis of AC and MM.

In plain English

This laboratory study from Turkey asked whether staining tumour tissue for a protein called maspin could help pathologists tell pleural epithelioid malignant mesothelioma apart from pulmonary adenocarcinoma (a lung cancer) that involves the pleura. The two cancers can look alike under the microscope. The authors examined surgical samples from 22 patients with pleural epithelioid mesothelioma and 22 with pulmonary adenocarcinoma, randomly selected from cases referred to Uludag University between 2002 and 2009. The article did not report on asbestos exposure. Maspin staining was found in 6 of the 22 mesotheliomas (27%) and in 13 of the 22 adenocarcinomas (59%), a statistically significant difference (P = 0.033). The adenocarcinomas also showed significantly more extensive and more intense staining, and none of the mesotheliomas stained strongly. Even so, used as a test for adenocarcinoma, maspin had a sensitivity of only 59% and a specificity of 73%. The authors concluded that this poor accuracy makes maspin of no value for distinguishing the two cancers. They noted that the study lacked a comparison group of pleural samples from normal lungs.

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 laboratory (immunohistochemistry) study comparing maspin staining in two tumour types
• Who was studied: Tumour samples from 22 patients with pleural epithelioid malignant mesothelioma (15 males, 7 females, mean age 61.0 years, range 37 to 79) and 22 patients with pulmonary adenocarcinoma with pleural involvement (20 males, 2 females, mean age 60.7 years, range 42 to 78). The patients were randomly selected from those referred to the Surgical Pathology Department of Uludag University School of Medicine, Bursa, Turkey, between 2002 and 2009. Sarcomatoid and biphasic mesotheliomas were excluded.
• Exposure: No asbestos exposure was studied or reported. The factor examined was maspin protein staining in tumour tissue.
• Main results:
  • Pleural epithelioid mesothelioma group: maspin staining was positive in 6 of 22 cases (27%), with weak expression in 2 (9%) and moderate expression in 4 (18%). It was absent in 16 (73%).
  • No pleural epithelioid mesothelioma case showed strong maspin expression.
  • Pulmonary adenocarcinoma group: maspin staining was positive in 13 of 22 cases (59%), with weak staining in 2 (9%), moderate in 5 (23%) and strong in 6 (27%). It was absent in 9 (41%).
  • Maspin positivity was significantly higher in the pulmonary adenocarcinoma group than in the pleural epithelioid mesothelioma group (P = 0.033).
  • Both the extent (P = 0.025) and the intensity (P = 0.014) of staining were significantly higher in the pulmonary adenocarcinoma group. The overall maspin score was also significantly higher in that group (P = 0.014).
  • As a test for adenocarcinoma, maspin positivity had a sensitivity of 59% and a specificity of 73%.
• The authors' conclusion: The authors concluded that maspin's poor accuracy makes it of no value in distinguishing pulmonary adenocarcinoma from malignant mesothelioma.
• Limitations the authors state:
  • There was no control group of pleural samples from normal lungs.
  • The authors stated that maspin expression in normal mesothelial cells, benign mesothelial proliferations and epithelioid mesothelioma needs detailed evaluation in a larger series of patients.

Topics

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

Medical terms in this study, explained in our Lexicon: Malignant Mesothelioma, Adenocarcinoma, Immunohistochemistry, Pleura, Epithelioid, Differential Diagnosis.

Related studies

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• Diagnostic efficacy of electron microscopy and pleural effusion cytology for the distinction of pleural mesothelioma and lung adenocarcinoma — H. Domínguez-Malagón, A.M. Cano-Valdez, et al. (2016)
• 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)
• Utility of a CEA, CD15, calretinin, and CK5/6 panel for distinguishing between mesotheliomas and pulmonary adenocarcinomas in clinical practice — T. Mohammad, J. Garratt, et al. (2012)
• Immunohistochemical distinction of malignant mesothelioma from pulmonary adenocarcinoma with anti-surfactant apoprotein, anti-Lewisa, and anti-Tn antibodies — M. Noguchi, T. Nakajima, et al. (1989)
• Distinction between pleural mesothelioma and pulmonary adenocarcinoma using MOC31 in an asbestos sprayer — P.J. Ryan, J.L. Oates, et al. (1997)

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