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HelpTest Code XL2T FOXL2 Mutation Analysis, Next-Generation Sequencing, Tumor
Ordering Guidance
Multiple oncology (cancer) gene panels are available. For more information see Hematology, Oncology, and Hereditary Test Selection Guide.
Necessary Information
A pathology report (final or preliminary), at minimum containing the following information, must accompany specimen for testing to be performed:
1. Patient name
2. Block number-must be on all blocks, slides, and paperwork (can be handwritten on the paperwork)
3. Tissue collection date
4. Source of the tissue
Specimen Required
This assay requires at least 20% tumor nuclei.
-Preferred amount of tumor area with sufficient percent tumor nuclei: tissue 216 mm(2)
-Minimum amount of tumor area: tissue 36 mm(2)
-These amounts are cumulative over up to 10 unstained slides and must have adequate percent tumor nuclei.
-Tissue fixation: 10% neutral buffered formalin, not decalcified
-For specimen preparation guidance, see Tissue Requirement for Solid Tumor Next-Generation Sequencing. In this document, the sizes are given as 4 mm x 4 mm x 10 slides as preferred: approximate/equivalent to 144 mm(2) and the minimum as 3 mm x 1 mm x 10 slides: approximate/equivalent to 36 mm(2).
Preferred:
Specimen Type: Tissue block
Collection Instructions: Submit a formalin-fixed, paraffin-embedded tissue block with acceptable amount of tumor tissue.
Acceptable:
Specimen Type: Tissue slides
Slides: 1 Stained and 10 unstained
Collection Instructions: Submit 1 slide stained with hematoxylin and eosin and 10 unstained, nonbaked slides with 5-micron thick sections of the tumor tissue.
Note: The total amount of required tumor nuclei can be obtained by scraping up to 10 slides from the same block.
Additional Information: Unused unstained slides will not be returned.
Specimen Type: Cytology slides (direct smears or ThinPrep)
Slides: 1 to 3 Slides
Collection Instructions: Submit 1 to 3 slides stained and coverslipped with a preferred total of 5000 nucleated cells, or a minimum of at least 3000 nucleated cells.
Note: Glass coverslips are preferred; plastic coverslips are acceptable but will result in longer turnaround times.
Additional Information: Cytology slides will not be returned.
Useful For
Assisting in the clinical diagnosis of adult granulosa cell tumor by assessing gene targets with in the FOXL2 gene
Special Instructions
Method Name
Sequence Capture and Targeted Next-Generation Sequencing (NGS)
Reporting Name
FOXL2 Mutations Analysis, TumorSpecimen Type
VariesSpecimen Minimum Volume
See Specimen Required
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Ambient (preferred) | ||
| Refrigerated | |||
Reject Due To
| Specimens that have been decalcified (all methods) Specimens that have not been formalin-fixed, paraffin-embedded, except for cytology slides Extracted nucleic acid (DNA/RNA) |
Reject |
Clinical Information
Granulosa cell tumors (GCT) represent approximately 5% to 10% of all ovarian malignancies and are the most common type of malignant ovarian sex-cord stromal tumors. The majority of GCT (95%) are adult type and 5% are juvenile type. Adult GCT can occur at any age but most commonly occur in perimenopausal women, whereas juvenile GCT arise in the first 3 decades of life. FOXL2 (forkhead box L2) gene is involved in ovarian development and function. The FOXL2 gene point mutation c.402C>G in exon 1 (p.C134W) has been reported in the majority of adult GCT (>90%), one molecular subtype of Sertoli-Leydig cell tumor, and rarely also in thecomas. In cases with challenging histopathology, detection of a FOXL2 mutation can aid in the clinical diagnosis of adult GCT.
This test uses formalin-fixed paraffin-embedded tissue or cytology slides to assess for the common somatic hotspot mutations in the FOXL2 gene. The results of this test can be useful for supporting a diagnosis of adult GCT.
Reference Values
An interpretive report will be provided.
Day(s) Performed
Monday through Friday
Report Available
12 to 20 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
88381 - Microdissection, manual
81479
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.