PURPOSEEven though non-Hodgkin's lymphoma is already sixth in incidence and mortality among malignant neoplasms (and the incidence was increasing at a rate of 3% to 4% per year before the advent of AIDS epidemic-associated lymphomas), most physicians and many oncologists find the disorder arcane. The problem lies in the complexity of human lymphoma, which encompasses more than a dozen neoplasms of the lymphoid system. The goal of this review is to provide user-friendly access to the condition.METHODSThe variety of inputs required for a subdivision of non-Hodgkin's lymphoma that is useful to clinicians includes lymphocyte lineage and sublineage based on microscopic appearance and immunophenotype, clinical behavior manifest in survival and early dissemination, and analysis of molecular genetic and cytogenetic abnormalities, which reflect pathogenic oncogene derangements. Epstein-Barr virus (EBV) and human T-cell leukemia virus type 1 (HTLV-1) are important in certain uncommon lymphomas.RESULTS AND CONCLUSIO...