Diffuse large cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma (NHL) in adults. It is an aggressive form of lymphoma that develops from the B-cells in the lymphatic system.

Overview

DLBCL is characterized by rapidly growing, tumorous masses that can occur in lymph nodes or in extranodal sites, including the gastrointestinal tract, testes, thyroid gland, skin, brain, and bone. The disease is often diagnosed at an advanced stage, with affected individuals typically presenting with a rapidly enlarging mass, often accompanied by B symptoms such as fever, night sweats, and weight loss.

Pathophysiology

The pathophysiology of DLBCL is complex and involves multiple genetic and epigenetic alterations. The disease is thought to originate from germinal center B-cells or post-germinal center B-cells, which have undergone somatic hypermutation and class switch recombination. Several genetic alterations have been identified in DLBCL, including translocations involving the BCL2, BCL6, and MYC genes, as well as mutations in the EZH2, CD79B, and MYD88 genes.

Diagnosis

The diagnosis of DLBCL is based on the histological examination of a biopsy specimen, typically obtained from an affected lymph node or extranodal site. The histology of DLBCL is characterized by a diffuse infiltration of large B-cells, with a size equivalent to or larger than normal macrophages or more than twice the size of a normal lymphocyte. Immunohistochemistry is used to confirm the B-cell origin of the lymphoma cells and to distinguish DLBCL from other types of lymphoma.

Treatment

The standard treatment for DLBCL is a combination of chemotherapy and immunotherapy, typically the R-CHOP regimen (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone). High-dose chemotherapy followed by autologous stem cell transplantation may be considered for patients with relapsed or refractory disease. Novel therapies, such as CAR-T cell therapy, are currently being investigated in clinical trials.

Prognosis

The prognosis of DLBCL is variable and depends on several factors, including the patient's age, performance status, and the presence of certain genetic alterations. The International Prognostic Index (IPI) is commonly used to predict the outcome in DLBCL.