MCQ IN MEDICINE

Detailed explanation-1: -T-cell acute lymphoblastic leukemia (T-ALL) is a neoplastic disease of T lymphoblasts involving both peripheral blood and BM. Normal CD markers of T lymphoblasts include TdT, CD2, CD5, CD7, and cCD3 (CD3 is often absent), but CD4 and CD8 are coexpressed [8].

Detailed explanation-2: -Terminal deoxynucleotidyl transferase (TdT)-negative T-cell lymphoblastic lymphoma is a variant of T-cell lymphoblastic lymphoma/T-cell lymphoblastic leukaemia. TdT is a marker of immaturity expressed in 90%-95% cases of lymphoblastic lymphoma and useful in differentiating it from other mature lymphomas/leukaemias.

Detailed explanation-3: -TDT levels have been examined in adult leukemia, and early results suggest elevated values are found primarily in lymphoblastic leukemia and are usually quite low in myeloblastic leukemia.

Detailed explanation-4: -It can be detected by enzyme assay or immunocytochemical staining. High levels of enzyme and increased numbers of TdT+ cells are found in some lymphoblastic leukemias and lymphomas. Analysis for TdT thus provides a useful adjunct in the differential diagnosis of leukemia.