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HelpTest Code 23FBG Fibroblast Growth Factor-23 (FGF23), In Situ Hybridization
Additional Testing Requirements
If additional interpretation or analysis is needed, request PATHC / Pathology Consultation along with this test.
Shipping Instructions
Attach the green pathology address label included in the kit to the outside of the transport container.
Necessary Information
A pathology/diagnostic report and a brief history are required.
Specimen Required
Supplies: Pathology Packaging Kit (T554)
Specimen Type: Formalin-fixed, paraffin-embedded tissue block
Specimen Volume: Entire block
Specimen Type: Tissue slides
Slides: 5 Unstained glass, positively charged slides with 5 (+ or -1)-microns formalin-fixed, paraffin-embedded tissue
Secondary ID
620249Useful For
Assessing fibroblast growth factor-23 (FGF23) expression
Method Name
In Situ Hybridization (ISH)
Reporting Name
Fibroblast Growth Factor-23, ISHSpecimen Type
SpecialSpecimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Special | Ambient (preferred) | ||
| Refrigerated | |||
Reject Due To
| Wet/frozen tissue Cytology smears Nonformalin fixed tissue Nonparaffin embedded tissue Noncharged slides ProbeOn slides |
Reject |
Clinical Information
Fibroblast growth factor-23 (FGF23) is a phosphaturic hormone that acts on the proximal renal tubules to block phosphate reuptake. Production of FGF23 by a particular mesenchymal tumor, phosphaturic mesenchymal tumor, is responsible for the great majority of cases of tumor-induced osteomalacia.
Interpretation
This test, when not accompanied by a pathology consultation request, will be answered as either positive or negative. If additional interpretation or analysis is needed, request PATHC / Pathology Consultation along with this test.
Cautions
Age of a cut paraffin section can affect immunoreactivity. Stability thresholds vary widely among published literature and are antigen dependent. Best practice is for paraffin sections to be cut within 6 weeks.
Clinical Reference
1. Carter JM, Caron BL, Dogan A, Folpe AL. A novel chromogenic in situ hybridization assay for FGF23 mRNA in phosphaturic mesenchymal tumors. AM J Surg Pathol. 2015;39:(1)75-83
2. Bhattacharyya N, Chong WH, Gafni RI, Collins MT. Fibroblast growth factor 23: State of the field and future directions. Trends Endocrinol Metab. 2012;23(12):610-618
3. Graham RP, Hodge JC, Folpe AL, et al. A cytogenetic analysis of 2 cases of phosphaturic mesenchymal tumor of mixed connective tissue type. Hum Pathol. 2012;43(8):1334-1338
4. Graham R, Krishnamurthy S, Oliveira A, Inwards C, Folpe AL. Frequent expression of fibroblast growth factor-23 (FGF23) mRNA in aneurysmal bone cysts and chondromyxoid fibromas. J Clin Pathol. 2012;65(10):907-909
5. Bahrami A, Weiss SW, Montgomery E, et al. RT-PCR analysis for FGF23 using paraffin sections in the diagnosis of phosphaturic mesenchymal tumors with and without known tumor induced osteomalacia. Am J Surg Pathol. 2009;33(9):1348-1354
6. Folpe AL, Fanburg-Smith JC, Billings SD, et al. Most osteomalacia-associated mesenchymal tumors are a single histopathologic entity-an analysis of 32 cases and a comprehensive review of the literature. Am J Surg Pathol. 2004;28(1):1-30
Method Description
In situ hybridization on sections of paraffin-embedded tissue.(Unpublished Mayo method)
Day(s) Performed
Monday through Friday
Report Available
5 to 8 daysSpecimen Retention Time
Until staining is completePerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
88365-Primary
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| 23FBG | Fibroblast Growth Factor-23, ISH | 104259-7 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 620250 | Interpretation | 50595-8 |
| 620251 | Participated in the Interpretation | No LOINC Needed |
| 620252 | Report electronically signed by | 19139-5 |
| 620253 | Material Received | 81178-6 |
| 620254 | Disclaimer | 62364-5 |
| 620255 | Case Number | 80398-1 |
Forms
If not ordering electronically, complete, print, and send a Immunohistochemical (IHC)/In Situ Hybridization (ISH) Stains Request (T763) with the specimen.