Test Details: Immunohistochemical testing is carried out on biopsy/resected tissue specimen. This testing helps to identify specific antigens (proteins) within tissue sections utilizing an antigen-specific antibody .CD45, also known as leukocyte common antigen (LCA), is a family of high molecular mass integral membrane glycoprotein molecules expressed on all hematopoietic cells except mature red cells and their immediate progenitors, megakaryocytes, and platelets. CD45 is a specific marker for hematopoietic and lymphatic tumours; nonetheless, less than 3% of B-cell lymphoma, about 10% of T-cell lymphoma, and about 30% of precursor B- and T-lymphoblastic lymphomas (ALL) lack the expression of CD45.