Study of malignant lymphomas from the aspect of immunoglobulin production.

Intracytoplasmic localization of immunoglobulins in neoplastic cells of malignant lymphomas was studied by both light and electron microscopic immunoperoxidase methods. This was demonstrated in 17 out of 71 cases submitted to light or electron microscopic immunoperoxidase methods. Out of 19 cases examined by the electron microscopic immunoperoxidase method, immunoglobulins were intracellularly identified in 10 cases; 3 out of 6 cases which were diagnosed as follicular lymphoma, 3 out of 5 cases of reticulosarcoma, 2 out of 6 cases of lymphosarcoma and 2 cases of immunoblastic sarcoma. Out of the above 10 cases, IgM was demonstrated in 9 cases except one of immunoblastic sarcoma in which IgA, IgG and IgM were identified intracellularly. In addition to these findings, our ultracytological and pathological studies have indicated that immunoglobulin-producing tumors can be classified into the following three major groups according to their cellular origin; germinal centers (group 1), primary follicles (group 2) and extrafollicular (group 3). Group 1 is comprised of follicular lymphoma and reticulosarcoma, group 2 lymphosarcoma, and group 3 immunoblastic sarcoma.