CD21, IHC without Interpretation [40016X]

Test Code

40016

CPT Codes
88342

Preferred Specimen

Minimum: 1 formalin-fixed, paraffin-embedded, tissue block, submitted in IHC Specimen Transport Kit, room temperature

Other Acceptable Specimens

Minimum: 3 unstained, positively charged slides, submitted in IHC Specimen Transport Kit, room temperature

Transport Container

IHC Specimen Transport Kit

Transport Temperature

Room temperature

Specimen Stability

Room temperature: Indefinitely
Refrigerated: Indefinitely
Frozen: Unacceptable

Methodology
Immunohistochemistry

Setup Schedule

Set up: Mon-Fri a.m.; Report available: Next day

Clinical Significance

CD21 antigen is a type I integral membrane glycoprotein of molecular weight 140 kD, which functions as the receptor for the C3d fragment of the third complement component. The CD21 molecule, present on mature B cells, is involved in transmitting growth-promoting signals to the interior of the B cell and acts as a receptor for Epstein-Barr virus. CD21 antigen is reported to be found in B cell chronic lymphocytic leukemias and in a subset of T cell acute lymphocytic leukemias, but is absent on T lymphocytes, monocytes, and granulocytes. CD21 antigen is also reported to be expressed in follicular dendritic cells and in follicular and centrocytic lymphomas, mature leukemias and lymphomas, and at high density in follicular dendretic cells.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.