CD34

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.

CD34 is a 110 kD cell surface antigen that is selectively expressed on the surface of vascular endothelium and hematopoietic progenitor cells. It is a sensitive but less specific marker for vascular neoplasms when compared to CD31. It also identifies a unique subset of mesenchymal tumors, including solitary fibrous tumor, gastrointestinal stromal tumor (GIST), myofibroblastoma, and dermatofibrosarcoma protuberans, and epithelioid sarcoma, among others. CD34 also facilitate the identification of blasts in acute myeloid leukemia.