CD21

Formalin-fixed, paraffin embedded tissue block or cell block, or 1 unstained charged slide for each test requested plus 3-4 additional unstained slides cut at 4 microns. Adequate space on each slide for control tissue is required.

CD21 is a valuable follicular dendritic cell marker, and, along with CD23 and CD35, is useful in the diagnosis of follicular dendritic cell tumors. It may also be used in assessing follicular dendritic cell meshwork in the lymphoid tissues, which may be effaced / altered by various disease processes and aid in the differential diagnoses of various types of lymphomas.