Diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a cancer of B cells, a type of lymphocyte that is responsible for producing antibodies. It is the most common form of non-Hodgkin lymphoma among adults, with an annual incidence of 7–8 cases per 100,000 people per year in the US and UK. This cancer occurs primarily in older individuals, with a median age of diagnosis at ~70 years, although it can occur in young adults and, in rare cases, children. DLBCL can arise in virtually any part of the body and, depending on various factors, is often a very aggressive malignancy. The first sign of this illness is typically the observation of a rapidly growing mass or tissue infiltration that is sometimes associated with systemic B symptoms, e.g. fever, weight loss, and night sweats. The causes of diffuse large B-cell lymphoma are not well understood. Usually DLBCL arises from normal B cells, but it can also represent a malignant transformation of other types of lymphoma (particularly marginal zone lymphomas) or, in rare cases termed Richter's transformation, chronic lymphocytic leukemia. An underlying immunodeficiency is a significant risk factor for development of the disease. Infections with the Epstein–Barr virus (EBV), Kaposi's sarcoma-associated herpesvirus, human immunodeficiency virus (i.e. HIV), and the Helicobacter pylori bacterium are also associated with the development of certain subtypes of diffuse large B-cell lymphoma. However, most cases of this disease are associated with the unexplained step-wise acquisition of increasing numbers of gene mutations and changes in gene expression that occur in, and progressively promote the malignant behavior of, certain B-cell types. Diagnosis of DLBCL is made by removing a portion of the tumor through a biopsy, and then examining this tissue using a microscope. Usually a hematopathologist makes this diagnosis. Numerous subtypes of DLBCL have been identified which differ in their clinical presentations, biopsy findings, aggressive characteristics, prognoses, and recommended treatments.