Diffuse large B cell lymphoma
|Diffuse large B cell lymphoma|
|Classification and external resources|
File:Diffuse large B cell lymphoma - cytology low mag.jpg|
Micrograph of a diffuse large B cell lymphoma. Field stain.
Two<ref name="Turgeon">Turgeon, Mary Louise (2005). Clinical hematology: theory and procedures. Hagerstown, MD: Lippincott Williams & Wilkins. pp. 285–286. ISBN 0-7817-5007-5. </ref> or three<ref name="pmid18765795">Lenz G, Wright GW, Emre NC, et al. (September 2008). "Molecular subtypes of diffuse large B-cell lymphoma arise by distinct genetic pathways". Proc. Natl. Acad. Sci. U.S.A. 105 (36): 13520–5. doi:10.1073/pnas.0804295105. PMID 18765795. PMC 2533222. http://www.pnas.org/cgi/pmidlookup?view=long&pmid=18765795. </ref> major subtypes of DLBL have been identified based on their genetic activity:
- activated (ABC-DLBCL), with a pattern of genetic expression that is similar to healthy, activated B cells, and
- germinal center (GCB-DLBCL), with a pattern of genetic expression that is similar to germinal center B cells and a chromosomal translocation involving the gene bcl-2. This type has a relatively favorable prognosis.<ref name="pmid17448534">Shiozawa E, Yamochi-Onizuka T, Takimoto M, Ota H (November 2007). "The GCB subtype of diffuse large B-cell lymphoma is less frequent in Asian countries". Leuk. Res. 31 (11): 1579–83. doi:10.1016/j.leukres.2007.03.017. PMID 17448534. http://linkinghub.elsevier.com/retrieve/pii/S0145-2126(07)00107-5. </ref>
- primary mediastinal B-cell lymphoma (PMBL) Where the cancer is found in the thymus gland and lymph nodes behind the sternum (mediastinum), the area between the lungs, in the middle of the chest.
Chromosome anomalies are:<ref>"Diffuse large cell lymphoma" at Atlas of Genetics and Cytogenetics in Oncology and Haematology</ref>
- t(14;18)(q32;q21) with BCL2-rearrangement.
- t(3;Var)(q27;Var) with BCL6-rearrangement. These are common translocations.<ref name="pmid16075463">Bosga-Bouwer AG, Haralambieva E, Booman M, et al. (November 2005). [Expression error: Missing operand for > "BCL6 alternative translocation breakpoint cluster region associated with follicular lymphoma grade 3B"]. Genes Chromosomes Cancer 44 (3): 301–4. doi:10.1002/gcc.20246. PMID 16075463. </ref>
- t(8;14)(q24;q32) with MYC rearrangements.
- and other less characteristic anomalies.
DLBCLs consists of cells that are 4-5 times the diameter of a small lymphocytes and typically have marked cell-to-cell variation in size and shape. Their cytoplasm is typically basophilic and moderate in abundance. Prominent nucleoli may be seen in some cases and may be peripheral and/or multiple. Large bizarre cells can occasionally mimic Reed-Sternberg cells, seen in Hodgkin lymphoma.
Standard treatment is CHOP. An expanded protocol, called CHOP-R, has improved survival<ref name="pmid17105812">Sehn LH, Berry B, Chhanabhai M, et al. (March 2007). "The revised International Prognostic Index (R-IPI) is a better predictor of outcome than the standard IPI for patients with diffuse large B-cell lymphoma treated with R-CHOP". Blood 109 (5): 1857–61. doi:10.1182/blood-2006-08-038257. PMID 17105812. http://www.bloodjournal.org/cgi/pmidlookup?view=long&pmid=17105812. </ref> and rates of complete responses for DLBL patients, particularly elderly patients.<ref name="Turgeon"/> R-CHOP is a combination of one monoclonal antibody, 3 chemotherapy drugs, and one steroid: rituximab (Rituxan), cyclophosphamide (Cytoxan) doxorubicin (Hydroxdaunorubicin), vincristine (Oncovin), and prednisone. Chemotherapy is most often administered intravenously and is most effective when it is administered multiple times over a period of months (eg. every 3 weeks, over 8-10 months). For someone who will be receiving chemotherapy it is suggested they have a PICC (Peripherally inserted central catheter) in their arm near the elbow, and the catheter will extend through one of the large veins to within centimeters of the heart. Radiation is another common treatment and is most effective if done prior to the chemotherapy, or as the last treatment after chemotherapy has been completed.
The germinal center subtype has the best prognosis, with 60% of treated patients surviving more than five years.<ref name="Turgeon"/>
|This article about a neoplasm is a stub. You can help Wikipedia by expanding it.|