Lysozyme

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.

Lysozyme is a glycoside hydrolase that is present in myeloid cells, histiocytes, granulocytes, and cells of macrophage/monocyte lineage. It is an immunohistochemical marker that may be useful in demonstrating myeloid or monocytic nature of acute leukemia. It is valuable in the work-up of soft tissue / cutaneous myeloid sarcoma / extramedullary myeloid tumor, particularly when only formalin-fixed tissue is available (without fresh tissue for flow cytometry studies).