Detection of intracellular immunoglobulin in nodular lymphomas

In lymph node tissue sections, six of 11 human cases of nodular lymphoma showed immunoglobulin within malignant nodules, and seven of nine cases of benign follicular hyperplasia showed immunoglobulin within follicles. In addition, distributions of lymphocyte cell membrane markers for T cells and B cells were determined in ten of 11 cases of nodular lymphoma. Lymphocyte suspensions in five cases contained monoclonal immunoglobulins and in three cases neoplastic cells showed a lack of surface membrane immunoglobulins. In two cases, the distribution of lymphocyte surface markers could not be distinguished from cells of benign lymph nodes. Combined data from intracytoplasmic immunoglobulin studies and lymphocyte surface marker assays indicated that eight of ten cases are of B cell lineage. Thus, the detection of intracellular immunoglobulin is not helpful in differentiating benign follicular hyperplasia from nodular lymphoma, but is complementary to lymphocyte surface marker assays in the determination of the origin of neoplastic cells in lymphoreticular malignancies.