[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.
Laboratoire d'Anatomie et Cytologie pathologiques, Hôpital Purpan, 1 place du Docteur Baylac, 31059 Toulouse . valmary.s@chu-toulouse.fr
Séverine
S
Valmary
Marie
M
Danjoux
Georges
G
Delsol
Pierre
P
Brousset
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