Alias/Synonym: Terminal Deoxynucleotidyl Transferase, Precursor B-cells, Cortical Thymocytes

CPT Code: 88342

Specimen Type, Preferred:
Formalin fixed paraffin embedded tissue
Specimen Type, Alternate:
Sample Quantity, Preferred:
1 block
2 slides
Sample Quantity, Minimum:
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:
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
Turnaround Time:
1 day(s)
Reference Ranges: