Synovial sarcoma of the pleura: a clinical and pathologic study of three cases

Our plain-English summary of Synovial sarcoma of the pleura: a clinical and pathologic study of three cases, by A.S. Colwell, J. D'Cunha, S.O. Vargas, et al (The Journal of Thoracic and Cardiovascular Surgery, 2002).

The study

• Authors: A.S. Colwell, J. D'Cunha, S.O. Vargas, B. Parker, P. Dal Cin, M.A. Maddaus
• Journal: The Journal of Thoracic and Cardiovascular Surgery
• Published: 2002;124(4):828-32
• Type of article: Case report
• Cited by: 21 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Synovial sarcomas are rare soft tissue malignancies that most commonly affect the extremities in the vicinity of large joints. These malignancies typically occur in adolescents and young adults between the ages of 15 and 40 years.(1,2) Historically they are believed to originate from primitive pluripotent mesenchyme capable of synovial differentiation. This belief is consistent with the malignancy's origin from sites devoid of normal synovium, such as the pleural cavity. A variety of pleural cavity sarcomas have been described, including liposarcoma,(3) chondrosarcoma,(4) osteosarcoma,(5) and malignant schwannoma.(6) Pleural synovial sarcoma, however, is a much rarer entity. In fact, pleural synovial sarcoma was first described only 6 years ago(7) and has not yet been reported in the surgical literature. Because of its rarity, pleural synovial sarcoma is often mistaken for the histologically similar malignant mesothelioma, the most common of the pleural neoplasms. This is a critical distinction, because synovial sarcoma may be extremely aggressive. Studies in the last 10 years have shown it to be extremely sensitive to ifosfamide-based chemotherapy, and survival of patients with synovial sarcoma has recently increased with chemotherapy, with 5-year survivals now as high as 57%.(8-10) In this report, we describe 3 cases of synovial sarcoma of the pleura. Clinical findings are correlated with pathologic features, including immunohistochemical stains and fluorescence in situ hybridization (FISH) for the identification of the diagnostic chromosomal translocation, t(X;18)(p11.2;q11.2). This delineation of the clinical and pathologic aspects of this rare, newly recognized tumor should increase awareness among the surgical community.

In plain English

This article reported three cases of synovial sarcoma of the pleura, a rare cancer that the authors said is often mistaken for malignant mesothelioma. The cases came from pathology files at Fairview-University Medical Center in Minneapolis. Tumor tissue was tested with special stains and with a genetic test (FISH) for the chromosome change t(X;18). The patients were a 39-year-old man, a 23-year-old woman and a 33-year-old man. The first man's pleural tumor was first diagnosed as sarcomatous malignant mesothelioma and was recognized as synovial sarcoma only after it spread. He died, with a follow-up of 8 years. The woman's pleural tumor was at one point diagnosed as mesothelioma, and she died 4 years after her first evaluation. The second man had the biphasic type and was alive without recurrence at 5 years. The genetic test found the chromosome change in the woman's tumor but not the first man's. For the second man the test failed, giving an indeterminate result. The article did not discuss asbestos. The authors concluded that correct, timely diagnosis of this tumor is essential for optimal therapy and survival.

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 series (report of 3 cases with clinical and pathologic review)
• Who was studied: 3 patients with synovial sarcoma of the pleura: a 39-year-old man, a 23-year-old woman and a 33-year-old man. They were identified from the primary and consultation files of the department of pathology at Fairview-University Medical Center, Minneapolis. Dates were not given.
• Exposure: No exposure was studied. The article does not mention asbestos or any other exposure. It concerns the diagnosis of pleural synovial sarcoma and how it is distinguished from malignant mesothelioma.
• Main results:
  • Patient 1 (39-year-old man): the thoracoscopic biopsy was interpreted as malignant mesothelioma, sarcomatous type. A muscle mass found 4 years later was diagnosed as synovial cell sarcoma. The original pleural tumor was then reviewed and judged in retrospect to be pleural synovial cell sarcoma.
  • Patient 1: after the cancer spread to the lung, doxorubicin chemotherapy reduced the number of lung nodules from 30 to 6. The patient later died. The table lists his status as dead with 8 years of follow-up.
  • Patient 2 (23-year-old woman): she had an earlier chest wall synovial sarcoma. A later pleural mass was identified by pathology as mesothelioma (not synovial sarcoma). Later recurrences were consistent with synovial sarcoma.
  • Patient 2 died 4 years after her initial evaluation.
  • Patient 3 (33-year-old man): the tumor was the biphasic type. After resection and no further treatment, he was alive without evidence of recurrent disease at 5 years.
  • FISH for t(X;18): negative in patient 1 and positive in patient 2. In patient 3 the test was attempted, but the probes did not hybridize, so no analysis was possible. The table lists his result as indeterminate.
  • Immunostains: pankeratin and epithelial membrane antigen showed diffuse staining in patients 1 and 3 and rare focal staining in patient 2. S100 was negative in all 3 cases.
• The authors' conclusion: The authors concluded that correct, timely diagnosis of this exceptionally uncommon tumor is essential for optimal therapy and survival.

Topics

Medical terms in this study, explained in our Lexicon: Synovial Sarcoma, Pleura, Pleural Cavity, Sarcoma, Malignant Mesothelioma, Neoplasm, Chemotherapy, Fluorescence In Situ Hybridization (FISH).

Related studies

• Synovial sarcoma of the pleura and its differentiation from other primary pleural tumours: a clinicopathological and immunohistochemical review of three cases — A.G. Nicholson, P. Goldstraw, et al. (1998)
• Pericardial synovial sarcoma, a potential for misdiagnosis: clinicopathologic and molecular cytogenetic analysis of three cases with literature review — Y. Cheng, W. Sheng, et al. (2012)
• The diagnostic utility of reduced immunohistochemical expression of SMARCB1 in synovial sarcomas: a validation study — J. Ito, N. Asano, et al. (2016)
• Calretinin and other mesothelioma markers in synovial sarcoma: analysis of antigenic similarities and differences with malignant mesothelioma — M. Miettinen, J. Limon, et al. (2001)
• 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)
• A biphasic tumor of the mediastinum with features of synovial sarcoma. A report of four cases — G.B. Witkin, M. Miettinen, et al. (1989)

Browse more research in The Journal of Thoracic and Cardiovascular Surgery, or return to medical research.