Test Method

IHC

CPT Code

88342 x 1
88341 x 1

Stains / Test Description

Anti-TdT antibody labels normal cortical thymocytes and primitive lymphocytes. Anti-TdT antibody detects an enzyme found in the nucleus of normal hematopoietic cells, normal cortical thymocytes and in the cytoplasm of megakaryocytes of the bone marrow. TdT expression is seen in over 90% of acute lymphoblastic lymphoma/ leukemia cases with the exception of pre-B-Cell ALL. TdT expression is not seen in normal mature T-or B-lymphocytes. Anti-TdT is positive for approximately one third of all cases of chronic myeloid leukemia, making it a good indicator of better response to chemotherapy.

Specimen Requirements

(1) H&E slide with formalin-fixed, paraffin-embedded (FFPE) tissue, fixed with 10% NBF.
or
One (1) unbaked, unstained slide for H&E staining (required) and two to three (2-3) positively charged unstained slides (all cut at 4 microns) for each test/antibody ordered

Block and slide identifiers should be clearly written and match exactly with the specimen ID and specimen labeling as noted on the requisition.

Storage & Transport

Ship specimen same day (whenever possible) with refrigerated (not frozen) cold pack

Turnaround time

1-3 days depending on level of service

Level of Service

Global (with interpretation)
Slide Only (glass slides only)
Web-Enabled (glass and digital images through eCSI portal)