The immunohistological detection of intracellular immunoglobulin in formalin-paraffin sections from multiple myeloma and related conditions using the immunoperoxidase technique.

Paraffin sections of tissues from thirty-three cases of plasma cell neoplasia have been examined by an immunoperoxidase method for demonstrating and characterizing intracellular immunoglobulins. The specificity of the method has been confirmed by a comparison of results with the serum paraprotein types analysed independently. The morphology of some of the immunoglobulin-containing cells is discussed and possible diagnostic applications of the method are briefly described.