Abstract
A high proportion of non-Hodgkin's lymphomas are neoplastic proliferations of B lymphocytes, and, as such, express integral membrane and/or cytoplasmic immunoglobulin (Ig). Because these cellular proliferations are monoclonal, the Ig of all neoplastic lymphocytes will have identical light chain type and idiotype. These tumors sometimes contain significant amounts of polyclonal Ig. In this study we demonstrate that the polyclonal non-B-lymphocyte-associated Ig may be removed by washing tissue at low pH to reveal either neoplastic B lymphocytes or neoplastic "null" lymphocytes. These observations should facilitate the application of immunohistology to the routine diagnosis of lymphoma.