TLE1 expression in malignant mesothelioma

Our plain-English summary of TLE1 expression in malignant mesothelioma, by A. Matsuyama, M. Hisaoka, M. Iwasaki, et al (Virchows Archiv, 2010).

The study

• Authors: A. Matsuyama, M. Hisaoka, M. Iwasaki, M. Iwashita, S. Hisanaga, H. Hashimoto
• Journal: Virchows Archiv
• Published: 2010;457(5):577-83
• Cited by: 40 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Malignant mesothelioma, an aggressive and often lethal tumor commonly associated with asbestos exposure, has been morphologically classified into epithelial, biphasic, and sarcomatoid subtypes. Histological distinction between biphasic or sarcomatoid mesothelioma and synovial sarcoma may be problematic in certain circumstances of intrathoracic location because of their similar clinicopathologic features, including not only their morphology but also occasional positive immunoreaction of mesothelioma markers. TLE1, which plays an important role in Wnt pathway, has been shown to be a specific marker for synovial sarcoma and diagnostically is useful; however, TLE1 expression in malignant mesotheliomas has not been fully evaluated. We immunohistochemically examined the expression of TLE1, factors related to the Wnt pathway including β-catenin and cyclin D1, and mesothelioma markers including calretinin, HBME-1, cytokeratin 5/6, and thrombomodulin in 29 malignant mesotheliomas. TLE1 was variably expressed in 28 malignant mesotheliomas regardless of histomorphological subtype with >25% of positive cells in 20 cases (69.0%). There was no evidence of association of TLE1 expression with immunoreactivity to other markers. Our study showed no or limited value of the immunohistochemical TLE1 expression in distinguishing malignant mesothelioma and synovial sarcoma.

In plain English

This laboratory study from Japan tested whether a tissue stain for a protein called TLE1 can help tell malignant mesothelioma apart from synovial sarcoma, a different tumor that can look similar under the microscope. The authors stained archived samples of 29 malignant mesotheliomas (27 pleural, one peritoneal, one pericardial) from 27 men and two women aged 51 to 85. Twenty-one of these patients had an occupational history of asbestos exposure. The authors also stained five synovial sarcomas, nine non-cancerous mesothelial lesions and seven lung carcinomas. TLE1 staining was seen in 28 of the 29 mesotheliomas (96.6%). In 20 cases (69.0%) it was present in 25% or more of tumor cells, in epithelioid, biphasic and sarcomatoid types alike, though somewhat weaker than in synovial sarcomas. All five synovial sarcomas and the non-cancerous mesothelial cells also stained for TLE1. TLE1 staining was not correlated with the usual mesothelioma markers. The authors concluded that TLE1 staining has no use, or only a supplementary role, in telling synovial sarcoma from mesothelioma.

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 (immunohistochemical) study of archived tumor tissue specimens
• Who was studied: 29 malignant mesotheliomas from the pathology files of the University of Occupational and Environmental Health, Kitakyushu, Japan. The patients were 27 men and two women aged 51 to 85 years. Of the tumors, 27 were pleural, one peritoneal and one pericardial; 12 were epithelioid, ten biphasic and seven sarcomatoid. For comparison the authors also examined five synovial sarcomas, nine non-neoplastic mesothelial lesions and seven lung carcinomas. Study dates are not given.
• Exposure: The study examined tissue staining for TLE1, beta-catenin, cyclin D1 and the mesothelioma markers calretinin, HBME-1, cytokeratin 5/6 and thrombomodulin. It did not study asbestos exposure as such. It reports that 21 patients had an occupational history of asbestos exposure and that this information was not available for two cases. No fiber types are named.
• Main results:
  • TLE1 was expressed in 28 of the 29 malignant mesotheliomas (96.6%).
  • In 20 of the 29 mesotheliomas (69.0%), TLE1 was scored 2+ or 3+ (positive in 25% or more of tumor cells). The staining was somewhat weaker than in synovial sarcomas.
  • By subtype, 2+ or 3+ TLE1 staining was seen in 13 of 22 (59.1%) mesotheliomas with epithelioid features and in 12 of 17 (70.6%) mesotheliomas with sarcomatoid features.
  • In the mesotheliomas, calretinin was positive in all 29, HBME-1 in 21 (72.4%), cytokeratin 5/6 in 20 (69.0%) and thrombomodulin in 24 (82.8%). None of these markers correlated with TLE1 expression.
  • In all the mesotheliomas, nuclear beta-catenin was confined to less than 5% of tumor cells. Cyclin D1 was expressed in 26 (89.7%) of the mesotheliomas, with 2+ or 3+ reactivity in 16 (55.2%).
  • TLE1 and cyclin D1 were positive in all five synovial sarcomas. Nuclear beta-catenin was seen in four of the five synovial sarcomas.
  • Non-neoplastic mesothelial cells were consistently positive for TLE1. Six of the seven lung carcinomas were negative for TLE1; the remaining adenocarcinoma expressed it focally.
• The authors' conclusion: The authors concluded that TLE1 staining is by no means specific for synovial sarcoma. In their view it has no use, or only a supplementary role, in distinguishing synovial sarcoma from mesothelioma.

Topics

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

Medical terms in this study, explained in our Lexicon: Malignant Mesothelioma, Asbestos Exposure, Biphasic Mesothelioma, Sarcomatoid, Mesothelioma, Synovial Sarcoma, Intrathoracic, Calretinin.

Related studies

• TLE1 is expressed in the majority of primary pleuropulmonary synovial sarcomas — L.S. Lino-Silva, J.P. Flores-Gutiérrez, et al. (2011)
• Pleural malignant mesothelioma versus pleuropulmonary synovial sarcoma: a clinicopathological study of 22 cases with molecular analysis and survival data — S. Klebe, S. Prabhakaran, et al. (2018)
• The diagnostic utility of reduced immunohistochemical expression of SMARCB1 in synovial sarcomas: a validation study — J. Ito, N. Asano, et al. (2016)
• Insulinoma-associated protein 1 is a sensitive and specific marker of neuroendocrine lung neoplasms in cytology specimens — E.E. Doxtader, S. Mukhopadhyay (2018)
• NY-ESO-1 expression in synovial sarcoma and other mesenchymal tumors: significance for NY-ESO-1-based targeted therapy and differential diagnosis — J.P. Lai, P.F. Robbins, et al. (2012)
• Loss of BAP1 expression is very rare in peritoneal and gynecologic serous adenocarcinomas and can be useful in the differential diagnosis with abdominal mesothelioma — J. Andrici, J. Jung, et al. (2016)

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