Terminal deoxynucleotidyl transferase by IHC

Alphabetical Test listing

Terminal deoxynucleotidyl transferase by IHC-12376 - Technical only, 12379 - Technical & interpretation

Test name:

Test number:

12376 - Technical only, 12379 - Technical & interpretation

Excellian order number:

LAB12376
LAB12379

Alternate names:

Tdt

Tests included:

All IHC stains will include a positive control tissue

Useful for:

Tdt identifies immature T and B lymphocyte precursors in acute leukemias. It is expressed at a high level in T cell and pre-B cell ALL and lymphoblastic lymphomas
Tdt is very useful on bone marrow trephines of leukemias where an adequate aspirate was unable to be obtained
B cell ALL (Burkitt type) and mature B and T cell malignancies are Tdt negative
Tdt may be expressed in some cases of AML and CML (blast crisis)
Tdt Expression is normally seen in the thymus (as well as in thymomas) and in a few cells in normal bone marrow (corresponding to normal precursor cells)

Specimen type:

Tissue

Processing instructions:

Submit a formalin-fixed, paraffin embedded tissue block

Transport container:

Formalin-fixed, paraffin embedded (FFPE) tissue block

Alternate transport container:

FFPE tissue section mounted on a charged, unstained slide

Transport and stability:

Ambient (preferred)

Reason for rejection:

Unlabeled/mislabeled block
Insufficient tissue
Slides broken beyond repair

Performing lab:

AHL - Immunohistochemistry

Days set up:

Mo - Fr

TAT:

1 - 2 days

Method:

Immunohistochemical staining and microscopic examination

Reference ranges:

If requested, an interpretive report will be provided

Clinical information:

Specifications

Tdt recognizes a DNA polymerase that is present in the nuclei of normal and neoplastic T and B lymphocyte precursors

Staining pattern

Nuclear based staining

References

Orazi et. al.: TdT Staining

CPT codes:

88342 - 1st stain
88341 - each additional stain

Date created:

09/13/2017

Revised date:

10/17/2018

Review date:

01/12/2024