Test Name: CD20
Methodology: Flow Cytometry
Staining for CD20 detects mature B-cells and precursor B-cells at some stages of maturation. It is also expressed at variable intensity in most mature B-cell non-Hodgkin lymphomas, many cases of precursor B lymphoblastic lymphoma/leukemia (typically weak and variable in the latter), and some myelomas [characteristically myeloma with t(11;14)]. While regarded as a highly specific B-lineage associated marker, it has been rarely found in some mature T-cell lymphomas and carcinomas. Notably, any of these B-cell neoplasms may become CD20-negative following therapy with agents targeting CD20 (e.g. Rituximab).
Testing for this antigen is typically performed as a part of the leukemia/lymphoma screening panel. For customized testing panels including this antigen, please contact the Medical Director of the Flow Cytometry laboratory.
Storage and Transport
Maintain specimen at room temperature. Do not refrigerate or freeze. Use cold pack for transport, making sure cold pack is not in direct contact with specimen.
Specimen Rejection Criteria
Turn Around Time (TAT): 24 hours
CPT Codes*: 88184, 88185, 88187, 88188, 88189
*The CPT codes provided with our Test Descriptions are based on AMA guidelines and are for informational purposes only. Correct CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed.