Synovial Sarcoma (SS), 18q11.2 (SS18 or SYT) Rearrangement, FISH, Tissue
Use
Synovial sarcoma is a malignant soft tissue tumor predominantly affecting the lower limbs of children and young adults. It accounts for approximately 5% to 10% of soft tissue tumors and often has a poor prognosis. The tumor can also be found in other regions such as the head and neck, heart, abdominal wall, mediastinum, and lung. Accurate diagnosis is crucial for treatment management, as the differential diagnosis can include various other sarcomas and tumor types. The SS18-SSX fusion transcript is a signature marker of this tumor, with a translocation involving chromosomes X and 18, present in about 90% of cases.
Special Instructions
A pathology report is required for performing the test. If a pathology consultation is desired, it must be ordered separately as the test itself does not include it. The report can include working drafts, preliminary, or surgical pathology reports. Adequate fixation methods must be used for effective FISH analysis, as non-formalin-fixed specimens or decalcified samples might not be suitable.
Limitations
The test is not FDA approved and is used as an adjunct to other clinical and pathological information. It is critical that the right fixative is used, as non-formalin fixatives may affect testing success. Poor quality RNA or rare translocation partners can lead to equivocal or falsely negative results in RT-PCR, thus FISH testing is a valuable adjunct for identifying SS18 gene rearrangements.
New York Approved
Methodology
Chromosomal / Cytogenetics (FISH)
Biomarkers
LOINC Codes
- 93810-0
- 50397-9
- 69965-2
- 62356-1
- 42349-1
- 31208-2
- 80398-1
- 85069-3
- 48767-8
- 18771-6
- 62364-5
Result Turnaround Time
7-10 days
Related Documents
For more information, please review the documents below
Specimen
Tissue (FFPE)
Volume
Not provided
Minimum Volume
Two consecutive, unstained, 5-micron-thick sections placed on positively charged slides and 1 hematoxylin and eosin-stained slide
Collection Instructions
Submit a formalin-fixed, paraffin-embedded (FFPE) tumor tissue block. Blocks prepared with alternative fixation methods may be acceptable; provide fixation method used.
Storage Instructions
Ambient (preferred), Refrigerated
Causes for Rejection
Paraffin-embedded tissues that have been decalcified are generally unsuccessful for FISH analysis.