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Test ID SYT Synovial Sarcoma by Reverse Transcriptase PCR (RT-PCR)

Useful For

Supporting a diagnosis of synovial sarcoma

Additional Tests

Test ID Reporting Name Available Separately Always Performed
SLIRV Slide Review in MG No, (Bill Only) Yes

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
SS18F SS18, Synovial Sarcoma, FISH, Ts Yes No

Testing Algorithm

This test is performed in conjunction with SLIRV / Slide Review in MG. Additional testing may be performed after review by pathologist. Upon approval from the requesting clinician, 70012 / Pathology Consultation may be added, if determined to be appropriate.

Method Name

Reverse Transcriptase Polymerase Chain Reaction (RT-PCR)/Gel Electrophoresis
(PCR is utilized pursuant to a license agreement with Roche Molecular Systems, Inc.)

Reporting Name

Synovial Sarcoma, RT-PCR

Specimen Type

Varies

A pathology/diagnostic report including a brief history is required.

 

Specimen Type:

Container/Tube: Surgical Pathology Packaging Kit (Supply T554) requested, but not required

Preferred: Formalin-fixed, paraffin-embedded (FFPE) tissue with a minimum of 10% tumor cell population

Acceptable: Unstained slides with a minimum of 10% tumor cell population; slides may be stained and/or scraped

Collection Instructions:

1. Process all specimens into FFPE blocks prior to submission.

2. If submitting slides, a minimum of ten, 4- to 5-micron thick, unstained slides are required.

Additional Information:

1. A quality specimen is essential for evaluation. Submit only tissue containing tumor cells; minimal tissue is required for evaluation.

2. Special stains performed outside Mayo Medical Laboratories and included with the case may be repeated and charged at the reviewing pathologist's discretion. Testing requested by the referring physician may not be performed if deemed unnecessary by Mayo Clinic pathologist.

Forms: If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

Pathology Test Request Form (T246) (http://www.mayomedicallaboratories.com/it-mmfiles/pathology-request-form.pdf)

Cardiovascular Test Request Form (T724) (http://www.mayomedicallaboratories.com/it-mmfiles/cardiovascular-request-form.pdf)

Oncology Test Request Form (T729) (http://www.mayomedicallaboratories.com/it-mmfiles/oncology-request-form.pdf)

Specimen Stability Information

Specimen Type Temperature Time
Varies Ambient (preferred)
  Frozen 
  Refrigerated 

Clinical Information

Synovial sarcomas account for 9% to 10% of soft tissue tumors. These tumors occur in 2 major forms: biphasic and monophasic. Monophasic tumors are composed entirely of spindle cells, while biphasic tumors have epithelial cells arranged in glandular structures and mixed with spindle cells. The tumors are usually positive for keratin and epithelial membrane antigen as well as vimentin by immunostaining.

 

Synovial sarcoma is a member of the small round-cell tumor group that includes rhabdomyosarcoma, lymphoma, Wilms tumor, Ewing sarcoma, and desmoplastic small round-cell tumor. While treatment and prognosis depend on establishing the correct diagnosis, the diagnosis of sarcomas that form the small round-cell tumor group by light microscopic examination alone can be very difficult, especially true when only small-needle biopsy specimens are available for examination. The use of immunohistochemical stains (eg, keratin and epithelial membrane antigen [EMA]) can assist in establishing the correct diagnosis, but these markers are not entirely specific for synovial sarcoma. Expertise in soft tissue and bone pathology are often needed.

 

Studies have shown that some sarcomas have specific recurrent chromosomal translocations. These translocations produce highly specific gene fusions that help define and characterize subtypes of sarcomas and are useful in the diagnosis of these lesions.(1-4)

 

Cytogenetic studies have shown a distinctive chromosomal translocation, t(X;18)(p11;q11), in more than 90% of synovial sarcomas. Cloning of the translocation breakpoint showed that t(X;18) results in the fusion of 2 genes designated as SS18 (at 18q11) and SSX (at Xp11). Two closely related genes, SSX1 and SSX2, have 81% homology in proteins. SS18-SSX1 is present in 55% of cases, while SS18-SSX2 is present in 35% of cases. Patients with SS18-SSX2 translocation usually have greater metastasis-free survival than those with SS18-SSX1.

 

These fusion transcripts can be detected by reverse transcriptase PCR (RT-PCR), by FISH, chromogenic in situ hybridization (CISH), or by classical cytogenetic analyses. The RT-PCR and FISH procedures are the most sensitive methods to detect these fusion transcripts.(3)

Reference Values

An interpretative report will be provided.

Cautions

Reliable results are dependent on adequate specimen collection and processing. This test has been validated on formalin-fixed, paraffin-embedded tissues; other types of fixatives are discouraged. Improper treatment of tissues, such as decalcification, may cause PCR failure. False-negative results may occur in tumor specimens when tumor cells comprise <10% of the cell population. Tumor cells may be enriched by macrodissection to avoid false-negative results. 

 

Clinical diagnosis and therapy should not be based solely on the results of this assay. The results should be considered in conjunction with clinical information, histologic evaluation, and additional diagnostic tests.

Day(s) Performed

Monday through Friday; Varies

Report Available

8 days

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

81401-EWSR1/FLI1

81401-EWSR1/ERG

88381-Microdissection, manual

 

NY State Approved

Yes