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HelpTest Code HK27M Histone H3 K27M Mutant (H3 K27M) Immunostain, Technical Component Only
Ordering 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.
Mayo Clinic Laboratories has multiple histone immunostains available. See table for ordering guidance.
|
Test ID |
Published name |
Indication |
Mayo Clinic slide label |
|
HG34W |
Histone 3.3 G34W (H3F3A G34W) Immunostain, Technical Component Only |
Giant cell tumor of bone (GCTB) |
H3 G34W |
|
HK27M |
Histone H3 K27M Mutant (H3 K27M) Immunostain, Technical Component Only |
K27M mutant midline gliomas |
H3 K27M |
|
HISME |
Histone H3 Trimethyl K27 (H3 K27me[3]) Immunostain, Technical Component Only |
MPNST and K27M mutant midline gliomas |
H3 K27me3 |
|
HK36M |
Histone H3 K36M Mutant (H3F3 K36M) Immunostain, Technical Component Only |
Chondroblastoma |
H3 K36M |
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
Specimen Type: Tissue
Supplies: Immunostain Technical Only Envelope (T693)
Container/Tube: Immunostain Technical Only Envelope
Preferred:
-Formalin-fixed, paraffin-embedded tissue block
OR
-2 Unstained, positively charged glass slides (25- x 75- x 1-mm) per test ordered; sections 4-microns thick
Acceptable: None
Useful For
Identifying the presence of altered H3 K27M protein
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| IHTOI | IHC Initial, Tech Only | No | No |
| IHTOA | IHC Additional, Tech Only | No | No |
Method Name
Immunohistochemistry (IHC)
Reporting Name
Histone H3 K27M IHC, Tech OnlySpecimen Type
TECHONLYSpecimen 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 Snowcoat slides |
Reject |
Clinical Information
Histone H3 K27M is an alteration in the H3F3A gene, encoding for histone H3.3. This alteration is characteristic of "diffuse midline glioma, H3 K27M-mutant," a new entity in the classification of central nervous system tumors, which carries a poor prognosis. H3 K27M-mutant diffuse midline glioma occurs most commonly in young children but, less frequently, can occur in adults. The most common locations include the brain stem, thalamus, and spinal cord. The term brain stem glioma and diffuse intrinsic pontine glioma were previously used to indicate tumors occurring in the brain stem and pons respectively.
Day(s) Performed
Monday through Friday
Report Available
1 to 3 daysPerforming 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
88342-TC, primary
88341-TC, if additional IHC
Forms
If not ordering electronically, complete, print, and send an Immunohistochemical (IHC)/In Situ Hybridization (ISH) Stains Request (T763) with the specimen.