Anomolous staining patterns in immunohistologic studies of malignant lymphoma

A number of immunoperoxidase studies of malignant lymphomas have reported polytypic light chain staining of neoplastic cells, thus bringing into question the concept that the monoclonality of B cell lymphomas is reflected in their synthesis of monotypic light chain. In this study of a large number of Ig positive lymphomas, staining for a wide variety of antigens has identified clear differences between monotypic Ig synthesizing cells and cells staining polytypically which appear to be taking up Ig from the environment. Attention to the nature of Ig staining and staining for J chain were the two most useful criteria in differentiating Ig synthesis from uptake. The results confirm that malignant B cell lymphomas synthesise monotypic Ig.