Introduction
Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin's lymphoma (NHL), accounting for 35–40% of all cases of NHL. Despite high reported response rates to anthracycline-based combination chemotherapy regimens, only 50–65% of patients with this disease have achieved long-term disease-free survival (DFS) with this approach. The emergence of new strategies, including monoclonal antibodies, dose-dense chemotherapy approaches, and the identification of new rational therapeutic targets by gene expression profiling, has resulted in improvements in outcome for patients with this disease in recent years.
Involvement ofextranodal sites, either as a primary site of disease or as sites of dissemination, is relatively common in DLBCL. With the exception of primary central nervous system (CNS) lymphoma (see Chapter 13) and some other specific anatomic sites, treatment recommendations for DLBCL are generally identical for nodal and extranodal disease, with the exception of single site non-lower limb DLBCL of the skin (see Chapter 15).
Clinical presentation
The clinical presentation of DLBCL, as with other types of NHL, is most commonly with painless lymphadenopathy. Approximately 25% of patients present with anatomically limited stage disease (clinical stage I or II), with the remaining 75% having more advanced (bulky stage II or stage III or IV) disease. Many patients will also experience constitutional (“B”)symptoms, including drenching night sweats, unexplained fevers, and unexplained weight loss of more than 10% of body weight.