Lymphoproliferative disorders are a very heterogeneous group of neoplastic diseases, which originate from malignant transformation of cells of the lymphoid system. Within broad limits, they include at least four main types of diseases: Hodgkin’s disease, the socalled non-Hodgkin’s lymphomas, the chronic lymphoid leukemias and the neoplasms of mature B antibody-producing cells, such as Waldenstr...