Diffuse large B-cell lymphoma

Abstract

The World Health Organization (WHO) classification defines diffuse large B-cell lymphoma (DLBCL) as a group of proliferations of large B-cell lymphoid cells with a diffuse growth pattern. It contains some specific entities and a large group of heterogeneous "not otherwise specified" diseases comprising morphologic variants and immunohistochemical, genetic, and molecular subgroups. DLBCL is the most common hematopoietic malignancy, accounting for one-third of mature B-cell neoplasms. Major advances have been observed in the knowledge and the management of DLBCL in the recent years. If the International Prognosis Index (IPI) is still the primary clinical tool used to predict outcome for patients with DLBCL and to guide therapeutic strategies, gene expression profiling and its related biomarkers delineate at least two major histologically indistinguishable molecular subtypes, the germinal center B-cell-like (GCB) subtype and the activated B-cell-like (ABC) subtype, that differ in cure rates and in responsiveness to targeted therapies, independently of the clinical variables. Functional imaging with fluorine-18 deoxyglucose (FDG) positron emission tomography (PET) has become an indispensable mean of assessing the extent of the disease and treatment response. The advent of rituximab has opened the era of targeted therapies in DLBCL and has markedly modified, in combination with chemotherapy, the outcomes in all DLBCL subgroups.