SS18-SSX Rearrangement in Synovial Sarcoma Using Fluorescent in Situ Hybridization: A Report from an Iranian Population and Literature Review

Safaei, Akbar; Jansar, Elham; Monabati, Ahmad; Mokhtari, Maral; Montazer, Mehdi

doi:10.30476/mejc.2020.82264.1073

SS18-SSX Rearrangement in Synovial Sarcoma Using Fluorescent in Situ Hybridization: A Report from an Iranian Population and Literature Review

Document Type : Original Article(s)

Authors

Akbar Safaei

Elham Jansar

Ahmad Monabati

Maral Mokhtari

Mehdi Montazer

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

https://doi.org/10.30476/mejc.2020.82264.1073

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

Synovial sarcoma

Gene fusion

Fluorescent in situ hybridization

SS18-SSX1 fusion protein

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.

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