Histopathology of DLCL
Diffuse Large B-Cell Lymphoma (DLCL) is prevalent type of non-Hodgkin's lymphoma, accounting for approximately one-third of all cases (ACS).
DLCLs most commonly appear in the lymph nodes, spleen, liver, and bone marrow. It is found system-wide, however, and may involve the central nervous system, lungs, gastrointestinal tract, genitourinary tract, and the bones. It has a high morbidity rate and spreads quickly
There are several subtypes and variants of DLCL:
Morphologic Variants
- Centroblastic
- Immunoblastic
- Anaplastic Large B-Cell
- Plasmablastic
- Anaplastic lymphoma kinase-positive
Subtypes
- Mediastinal (thymic) large B-cell lymphoma
- Intravascular large B-cell lymphoma
- T-cell/histiocyte-rich large B-cell lymphoma
- Lymphomatoid granulomatosis-type large B-cell lymphoma
- Primary effusion lymphoma
Affects Adults and Children
The median age of people at diagnosis is 57, with a range of 10-88 years, most often in people in their 70s.
Large cell lymphomas also one of the more common NHLs in children, accounting for about 20-25% of childhood lymphomas.
Generally Aggressive
As aggressive malignancies with a tendency to metastasize, the majority eventually demonstrate some
extranodal component, including the gastrointestinal tract, testes, thyroid, skin, breast,
central nervous system or
bone. Although generally extra-nodal involvement is more common than in follicular lymphomas, the marrow is involved only about 10% of the time.
DLCL can arise from other types of lymphoma including small B-cell lymphoma, follicular lymphoma, or marginal zone lymphoma - this is called transformed diffuse large cell lymphoma. Armitage et al. state that DLCL that occurs in sites where MALT lymphomas are found are best labeled DLCL rather than a transformed lymphoma.
Causes
There is strong evidence of a genetic factor in DLCL. 15% to 30% of the cases have a t(14;18), BCL-2 gene rearrangement. The c-MYC gene is rearranged in 5-15% of cases. The BCL6 gene is rearranged in 20-40% of cases and has some mutations in a noncoding region in 70% of cases.
Treatment
Recent advances in tissue testing allow medical personnel to recognize the exact features of DLCL, allowing them to select the therapy that may work best given the lymphoma characteristics.
Combination chemotherapy containing adriamycin (such as CHOP) is often used in DLCL with or without follow-up radiation. Stem Cell transplants have been used when the above treatments have not been effective or for relapsed lymphoma.
Use of monoclonal antibody therapy, using drugs such as rituxan have occurred in trials and use of these drugs with or without CHOP may be the upcoming standard in treatment.
Dive Deeper
Non-Hodgkin's Lymphoma Information Pages:
Childhood Lymphoma Information Pages:
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