Positive TTF-1 Expression in Malignant Mesothelioma: A Case Report

Our plain-English summary of Positive TTF-1 Expression in Malignant Mesothelioma: A Case Report, by G. Richter, H. Heidersdorf, D. Hirschfeld, et al (The American Journal of Case Reports, 2016).

The study

• Authors: G. Richter, H. Heidersdorf, D. Hirschfeld, F. Krebbel
• Journal: The American Journal of Case Reports
• Published: 2016;17:133-6
• Type of article: Case report
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: The histopathological diagnosis of malignant mesothelioma is based mainly on the immunohistological profile of the neoplasia, using different immunohistochemical markers to distinguish between a malignant mesothelioma and a carcinoma.

Case Report: A female patient presented with a right paravertebral rapidly growing tumor and severe pain. Based on the immunohistochemical findings, we present the first case of a malignant mesothelioma with immunohistochemical expression of thyroid transcription factor-1.

Conclusions: The detection of a positive reaction for thyroid transcription factor-1 in the tumor cells may not exclude a malignant mesothelioma.

In plain English

This case report described a single patient, a 70-year-old woman. Over about four weeks she developed a rapidly growing, painful tumor beside the upper right thoracic spine. A CT scan showed a 6×5 cm lesion extending from the pleura through the chest wall and beginning to erode the 4th rib. She had worked as a commercial clerk, and the authors reported no particular work-related exposure to asbestos or radiation. A needle biopsy was diagnosed as malignant mesothelioma. The tumor cells tested negative for cytokeratin 7 and cytokeratin 20. They tested positive for cytokeratin 5/6, calretinin, D2-40 and WT-1, and also for TTF-1, a marker the authors said had until then seemed to rule out mesothelioma. A consultant from the German mesothelioma register confirmed the finding. She received cisplatin chemotherapy with palliative radiation (total dose 50.0 Gy). At the end of therapy, ultrasound showed a 50% tumor reduction, and four months later no growth was detected. The authors called this the first reported case of its kind. They concluded that a positive TTF-1 reaction may no longer exclude malignant 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: case report (single patient)
• Who was studied: One 70-year-old white woman with a rapidly growing right paravertebral tumor, described by authors based in Hameln, Germany. She had stable B-cell chronic lymphocytic leukemia under observation since 2003 and slowly advancing Alzheimer disease.
• Exposure: She worked as a commercial clerk. The authors reported no particular work-related exposure to asbestos or radiation. No asbestos exposure is described.
• Main results:
  • CT showed a 6×5 cm lesion with the beginning of shallow erosion of the 4th rib on the right. The lesion extended from the pleura through the chest wall.
  • The tumor cells were negative for cytokeratin 7 and cytokeratin 20.
  • The tumor cells were positive for cytokeratin 5/6 and calretinin, and also for D2-40 and WT-1.
  • The tumor cells of this malignant mesothelioma were positive for TTF-1.
  • The finding was confirmed by consultation with Professor A. Tannapfel, director of the German mesothelioma register at Ruhr University Bochum.
  • Treatment combined weekly cisplatin at 20 mg/m2 (cumulative dose 240 mg) with radiation given in 2.5 Gy doses, 5 times a week, to a total dose of 50.0 Gy.
  • The radiation was given in a palliative setting.
  • At the end of therapy the tumor was reduced by 50%, as measured by ultrasound. Four months later no growth was detected, and the patient required no pain medication.
• The authors' conclusion: The authors concluded that, although detection of TTF-1 had until now seemed to rule out malignant mesothelioma, a positive TTF-1 reaction may no longer exclude it. They described this as the first report of a malignant mesothelioma with positive TTF-1 expression.

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: Thyroid Transcription Factor-1 (TTF-1), Mesothelioma, Carcinoma.

Related studies

• Napsin A and thyroid transcription factor-1 expression in carcinomas of the lung, breast, pancreas, colon, kidney, thyroid, and malignant mesothelioma — J.A. Bishop, R. Sharma, et al. (2010)
• Expression of thyroid transcription factor-1 in malignant pleural effusions — A. Khoor, A.L. Byrd-Gloster, et al. (2011)
• An immunohistochemical comparison of two TTF-1 monoclonal antibodies in atypical squamous lesions and sarcomatoid carcinoma of the lung, and pleural malignant mesothelioma — S. Klebe, A. Swalling, et al. (2016)
• Gene expression of surfactant protein-A and thyroid transcription factor-1 in lungs of rats exposed to silicon-carbide whisker in vivo — Y. Morimoto, L. Ding, et al. (2003)
• Expression of snail, twist, and Zeb1 in malignant mesothelioma — H. Merikallio, P. Pääkkö, et al. (2013)
• The diagnostic role of PTEN and ARID1A in serous effusions — B. Davidson, M. Pinamonti, et al. (2018)

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