thymus, thymoma, some cells within tonsils
Regulatory status: IVD, FDA Class I
8243-C010: RTU, 10 capsules; 1 pack
8243-M250: RTU, 250 tests, 1 cartridge; 1 unit
Terminal deoxynucleotidyl transferase (TdT) is a deoxynucleotide polymerizing enzyme that generates antigen receptor diversity at the junctions of rearranged immunoglobulin heavy chain and T-cell receptor gene segments. TdT protein expression is normally found only in B-cell and T-cell lymphoblasts/lymphoid progenitor cells. TdT protein-positive cells are regularly detected in thymus and bone marrow, and may occasionally be seen in tonsils, lymph nodes, and extranodal lymphoid tissue.
Strong staining of the infiltrating immature T-cells is seen in this thymoma.
The neoplastic epithelial component is negative.
Mature T- and B-cells of the tonsil are negative for TdT. Scattered immature T-Cells of the interfollicular areas may show strong nuclear staining.