ABSTRACT
The WHO classification of hematopoietic tumors is presented in Table 3.1. Figures 3.1 and 3.2 present algorithms for the diagnostic approach for hematopoietic tumors.
B-CELL LYMPHOPROLIFERATIONS Non-Hodgkin’s lymphomas are classified into numerous histologic and phenotypic subtypes and generally can be divided into indolent (low grade) and aggressive (high grade). In the B-cell category, low-grade lymphomas include SLL/CLL, FL, marginal zone B-cell lymphoma (MALT lymphoma), and lymphoplasmacytic lymphoma/Waldenström macroglobulinemia.The aggressive group comprises DLBCL and its variants, Burkitt lymphoma, mediastinal (thymic) large B-cell lymphoma, and plasmablastic lymphoma. However, even within a specific category, patients vary considerably with regard to outcome (e.g. BL is more aggressive clinically than DLBCL), and therefore chromosomal and molecular testing is often needed to better characterize the lymphoma in individual patients. Some lym-
suggesting high grade, have a particularly poor prognosis when treated with multiagent chemotherapy alone (e.g. B-prolymphocytic leukemia and MCL). Figure 3.3 presents an algorithm for the diagnosis of mature B-cell lymphoproliferations. Common chromosomal translocations in B-cell lymphomas are presented in Table 3.2.
