TdT
Alias/Synonym: Terminal Deoxynucleotidyl Transferase, Precursor B-cells, Cortical Thymocytes
CPT Code: 88342
- Includes:
- Specimen Type, Preferred:
- Formalin fixed paraffin embedded tissue
- Specimen Type, Alternate:
- Sample Quantity, Preferred:
- 1 block
- 2 slides
- Sample Quantity, Minimum:
- N/A
- Transport Container:
- Paraffin block
- Unstained slides
- Transport Temperature:
- Room temperature
- Collection Instructions:
- Block and slide identifiers should be clearly written and match exactly with the specimen ID and specimen labeling as noted on the requisition.
- Slides should be positively charged and cut at 3-4 microns for each stain/antibody ordered.
- Specimen Stability:
- N/A
- Rejection Criteria:
- No liquid specimens.
- Uncharged slides
- Clinical Significance:
- TdT (terminal deoxynucleotidyl transferase) is reported to be expressed in primitive T and B lymphocytes of the normal thymus and bone marrow. It catalyzes the addition of deoxynucleotides to the 3'-hydroxyl terminus of oligonucleotide primers, and generates antigen receptor diversity by inserting non-germ line elements at the junctions of rearranged Ig heavy chain and T cell receptor gene segments. Uniform and strong TdT expression is typically seen in pre-B and pre-T ALL/LBL, with weaker expression in Burkitt lymphoma. It may also be positive in AML
- Limitations:
- Turnaround Time:
- 1 day(s)
- Reference Ranges:
- N/A