[Diagnostic value of anti-terminal deoxynucleotidyl transferase antibody (TdT) in hematologic pathology].
OBJECTIVE
The diagnosis of primitive hematologic malignancies depends on a panel of monoclonal antibodies which is growing over time. The distinction between immature (lymphoblastic lymphoma/acute lymphoblastic leukaemia) and mature lymphoma is sometimes difficult. In this study, we evaluated anti-TdT antibody in the diagnosis and classification of these proliferations.


METHODS
13 lesions were examined by immunohistochemistry: 4 B and T lymphoblastic lymphomas, 2 Burkitt's lymphomas, 5 B and T acute lymphoblastic leukemias and 2 acute monoblastic leukemias.


RESULTS
TdT expression is specific of immature lymphoid proliferations (T or B lymphoblasts). TdT is not expressed by mature B or T cell lymphomas such as Burkitt's lymphomas. Significant numbers of cases of acute myeloblastic leukemias are TdT positive but could be easily distinguished from lymphoblastic proliferations.


CONCLUSIONS
Anti-TdT antibody represents a useful marker for differentiating lymphoma/acute lymphoblastic leukemia from other lymphomas. This marker, available in routine diagnosis should be systematically included in the panel of antibodies used for immunophenotyping hematologic malignancies.
Valmary
Séverine
S
Laboratoire d'Anatomie et Cytologie pathologiques, Hôpital Purpan, 1 place du Docteur Baylac, 31059 Toulouse . valmary.s@chu-toulouse.fr
Danjoux
Marie
M
Delsol
Georges
G
Brousset
Pierre
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D000906:Antibodies; D002051:Burkitt Lymphoma / Q000175:diagnosis; D002648:Child; D004253:DNA Nucleotidylexotransferase / Q000032:analysis* / Q000276:immunology*; D003937:Diagnosis, Differential; D005260:Female; D019337:Hematologic Neoplasms / Q000145:classification / Q000175:diagnosis* / Q000201:enzymology; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D007948:Leukemia, Monocytic, Acute / Q000175:diagnosis; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000175:diagnosis; D016393:Lymphoma, B-Cell / Q000175:diagnosis; D016399:Lymphoma, T-Cell / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis
D000906:Antibodies; D004253:DNA Nucleotidylexotransferase