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HelpTest Code TTFSP Thyroid Transcription Factor (SPT24) Immunostain, Technical Component Only
Reporting Name
TTF1 (SPT24) IHC, Tech OnlyUseful For
Part of a panel of immunostains to identify the primary site for carcinomas of unknown origin
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| IHTOI | IHC Initial, Tech Only | No | No |
| IHTOA | IHC Additional, Tech Only | No | No |
Testing Algorithm
For the initial technical component only immunohistochemical (IHC) stain performed, the appropriate bill-only test ID will be reflexed and charged (IHTOI). For each additional technical component only IHC stain performed, an additional bill-only test ID will be reflexed and charged (IHTOA).
Method Name
Immunohistochemistry (IHC)
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
TECHONLYOrdering Guidance
This test includes only technical performance of the stain (no pathologist interpretation is performed). If diagnostic consultation by a pathologist is required order PATHC / Pathology Consultation.
Shipping Instructions
Attach the green "Attention Pathology" address label (T498) and the pink Immunostain Technical Only label included in the kit to the outside of the transport container.
Specimen Required
Supplies: Immunostain Technical Only Envelope (T693)
Specimen Type: Tissue
Container/Tube: Immunostains Technical Only Envelope
Preferred: 2 Unstained positively charged glass slide (25- x 75- x 1-mm) per test ordered; sections 4-microns thick.
Acceptable: Formalin-fixed, paraffin-embedded tissue block
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| TECHONLY | Ambient (preferred) | ||
| Refrigerated | |||
Reject Due To
| Wet/frozen tissue Cytology smears Nonformalin fixed tissue Nonparaffin embedded tissue Noncharged slides ProbeOn slides |
Reject |
Day(s) Performed
Monday through Friday
CPT Code Information
88342-TC, primary
88341-TC, if additional IHC
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| TTFSP | TTF1 (SPT24) IHC, Tech Only | Order only;no result |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 70888 | TTF1 (SPT24) IHC, Tech Only | Bill only; no result |
Secondary ID
70576Clinical Information
Thyroid transcription factor 1 (TTF1) is a nuclear protein expressed in thyroid follicular cells, type II pneumocytes, and a subset of bronchial cells. Given its relative specificity for cells of thyroid or lung origin, this immunostain is often included in a panel to identify the primary site for carcinomas of unknown origin.
Interpretation
This test does not include pathologist interpretation, only technical performance of the stain. If interpretation is required, order PATHC / Pathology Consultation for a full diagnostic evaluation or second opinion of the case.
The positive and negative controls are verified as showing appropriate immunoreactivity. If a control tissue is not included on the slide, a scanned image of the relevant quality control tissue is available upon request; call 855-516-8404.
Interpretation of this test should be performed in the context of the patient's clinical history and other diagnostic tests by a qualified pathologist.
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. Bejarano PA, Nikiforov YE, Swenson ES, Biddinger PW. Thyroid transcription factor-1, thyroglobulin, cytokeratin 7, and cytokeratin 20 in thyroid neoplasms. Appl Immunohistochem Mol Morphol. 2000;8(3):189-194
2. Comperat E, Zhang F, Perrotin C, et al. Variable sensitivity and specificity of TTF-1 antibodies in lung metastatic adenocarcinoma of colorectal origin. Mod Pathol. 2005;18(10):1371-1376
3. Folpe AL, Gown AM, Lamps LW, et al. Thyroid transcription factor-1: immunohistochemical evaluation in pulmonary neuroendocrine tumors. Mod Pathol. 1999;12(1):5-8
4. Matoso A, Singh K, Jacob R, et al. Comparison of thyroid transcription factor-1 expression by 2 monoclonal antibodies in pulmonary and nonpulmonary primary tumors. Appl Immunohistochem Mol Morphol. 2010;18(2):142-149
5. Yatabe Y, Mitsudomi T, Takahashi T. TTF-1 expression in pulmonary adenocarcinomas. Am J Surg Pathol. 2002;26(6):767-773
6. Magaki S, Hojat SA, Wei B, So A, Yong WH. An introduction to the performance of immunohistochemistry. Methods Mol Biol. 2019;1897:289-298. doi:10.1007/978-1-4939-8935-5_25
Method Description
Immunohistochemistry on sections of paraffin-embedded tissue.(Unpublished Mayo method)
Report Available
1 to 3 daysSpecimen Retention Time
Until staining is complete.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.Forms
If not ordering electronically, complete, print, and send a Immunohistochemical (IHC)/In Situ Hybridization (ISH) Stains Request (T763) with the specimen.