Document Type : Original Article(s)

Authors

Department of Pathology, Shiraz University of Medical Sciences, Shiraz, Iran

Abstract

Background: Synovial sarcoma is an aggressive soft tissue sarcoma. It has a wide spectrum of histopathologic patterns and uncertain immunohistochemistry, rendering it a diagnostic challenge. The objective of this study was to investigate the diagnostic utility and impact of SS18-SSX rearrangement evaluation in an Iranian population previously diagnosed with synovial sarcoma without such molecular tests.
Method: We conducted this cross-sectional study on 44 formalin-fixed paraffin-embedded tissue blocks obtained from 23 synovial sarcoma patients (males, 69%; mean age, 36.4 years) and 11 cases with other neoplasms as negative controls. We assessed these specimens for SSX-SS18 gene rearrangement by break-apart fluorescent in situ hybridization (FISH) probes.
Results: FISH study showed SS18-SSX fusion gene in 17 (73.91%) cases while six (26.09%) cases and negative controls did not show SS18-SSX fusion. Histopathologic type of tumor was significantly related to the presence of rearrangement (P=0.002) (rearranged: 11 biphasic and six monophasic tumors; non-rearranged: three monophasic and three poorly-differentiated tumors).
Conclusion: This study supports the idea that molecular studies contribute to the confirmation of synovial sarcoma diagnosis, particularly in monophasic and poorly-differentiated subtypes, which show vague immunohistochemical results.

Keywords

How to cite this article:

Safaei A, Jansar E, Monabati A, Mokhtari M, Montazer M. SS18-SSX rearrangement in synovial sarcoma using fluorescent in situ hybridization: A report from an Iranian population and literature review. Middle East J Cancer. 2020;11(4): 476-82. doi: 10.30476/mejc. 2020.82264.1073.

  1. Goldblum JR,‎ WeissSW,‎ Folpe Al. Enzinger and Weiss's Soft Tissue Tumors. 6th ed. Philadelphia: Saunders; 2014. p. 1052-1070.
  2. Goldblum JR, Lamps WL, McKenney JK, Myers JL. Rosai and Ackerman's surgical pathology. 11th ed. Amsterdam: Elsevier; 2018. p. 1876-1879.
  3. McPherson R, Pincus MR. Henry’s clinical diagnosis and management by laboratory methods. 23rd ed. Amsterdam: Elsevier; 2017. p .1514.
  4. Motoi T, Kumagai A, Tsuji K, Imamura T, Fukusato T. Diagnostic utility of dual-color break-apart chromogenic in situ hybridization for the detection of rearranged SS18 in formalin-fixed, paraffin-embedded synovial sarcoma. Hum Pathol. 2010;41(10):1397-404. doi: 10.1016/j.humpath.2010.02.009.
  5. Tvrdík D, Povýsil C, Svatosová J, Dundr P. Molecular diagnosis of synovial sarcoma: RT-PCR detection of SYT-SSX1/2 fusion transcripts in paraffin-embedded tissue. Med Sci Monit. 2005;11(3):MT1-7.
  6. Romeo S, Rossi S, Acosta Marín M, Canal F, Sbaraglia M, Laurino L, et al. Primary Synovial Sarcoma (SS) of the digestive system: a molecular and clinicopathological study of fifteen cases. Clin Sarcoma Res. 2015 12;5:7. doi: 10.1186/s13569-015-0021-3.
  7. Surace C, Panagopoulos J, Palsson E, Rocchi M, Mandahl N, Mertens F. A novel FISH assay for SS18–SSX fusion type in synovial sarcoma. Lab Invest. 2004;84:1185-92. doi: 10.1038/labinvest.3700142.
  8. Horna H, Allmanritter J, Doglionid C, Marxe A, Müllerb J, Gattenlöhnerf S, et al. Fluorescence in situ analysis of soft tissue tumor associated genetic alterations in formalin-fixed paraffin-embedded tissue. Pathol Res Pract. 2014;210:804-11. doi: 10.1016/j.prp.2014.09.009.
  9. Munir R. Tanas, Brian P. Rubin, Raymond R. Tubbs, Steven D. Billings, Erinn Downs-Kelly, John R. Goldblum, Utilization of Fluorescence In Situ Hybridization in the Diagnosis of 230 Mesenchymal Neoplasms. Arch Pathol Lab Med. 2010;134:1797-803. doi: 10.1043/2009-0571-OAR.1.
  10. Amary MFC, Berisha F, Bernardi FDC, Herbert A, James M, Reis-Filho JS, et al. Detection of SS18-SSX fusion transcripts in formalin-fixed paraffin-embedded neoplasms: analysis of conventional RT-PCR, qRT-PCR and dual color FISH as diagnostic tools for synovial sarcoma. Mod Pathol. 2007;20:482-96. doi: 10.1038/modpathol.3800761.
  11. Terry J, Barry TS, Horsman DE, Hsu FD, Gown AM, Huntsman DG, et al. Fluorescence in situ hybridization for the detection of t(X;18)(p11.2;q11.2) in a synovial sarcoma tissue microarray using a break apart-style probe. Diagn Mol Pathol. 2005;14:77-82. doi: 10.1097/01.pas.0000155021.80213.c9.