The monoclonal antibody against IgD reacts with immunoglobin D delta chains. In tonsil and lymph node, immunohistochemical staining for IgD immunoglobulin heavy chain is usually used to highlight the tonsil and nodal architecture since the IgD antibody stains mantle zone cells in secondary follicles and mantle cells in primary follicles. It has been reported that IgD can be detected in the surface/cytoplasm of neoplastic cells of common small B lymphoid cell lymphomas, such as small lymphocytic lymphoma, mantle cell lymphoma, marginal zone lymphoma (especially splenic marginal zone lymphoma), and follicular lymphoma expression in L & P cells of nodular lymphocyte predominant Hodkin lymphoma has been seen. The IgD positive L & P cells are usually located in the extrafollicular area with a relatively T-cell-rich background IgD expression is rarely seen in T-cell rich B-cell lymphoma.