Specialties: Hematopathology

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.¹ 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.^1-2 IgD expression in L & P cells of nodular lymphocyte predominant Hodkin lymphoma has been seen in subsets of cases (27% to 71.4%).^1-3 The IgD positive L & P cells are usually located in the extrafollicular area with a relatively T-cell-rich background.^1,3 IgD expression is rarely seen in T-cell rich B-cell lymphoma. Studies have demonstrated that Reed-Sternberg cells of classic Hodgkin lymphoma are negative for IgD.^1,3 IgD multiple myeloma is a rare bone marrow plasma cell dyscrasia and can be identified by the IgD antibody, especially when a dry tap is encountered.⁴