Abstract
Non-Hodgkin's lymphomas are a heterogeneous group of disorders. Approximately 85 percent of them originate from B lymphocytes, and these B-cell lymphomas fall into the following main groups: lymphocytic lymphoma, follicular-center-cell lymphoma, mantle-cell lymphoma, diffuse large-cell lymphoma, and Burkitt's lymphoma. The mucosa-associated lymphoid-tissue (MALT) lymphomas, which occur in mucosal sites such as the stomach, form a separate category and may have a large-cell morphology. Of these various types, about 40 percent are diffuse large-cell lymphomas. In addition to distinctive cell-surface markers, there are characteristic genetic abnormalities in some kinds of lymphoma (Figure 1). These genetic disturbances often follow breakage of chromosomes . . .