Diffuse large B cell lymphoma

Diffuse large B-cell lymphoma (DLBL, DLBCL, or DLCL) is a type of aggressive lymphoma. It accounts for approximately 40% of lymphomas among adults.&lt;ref&gt; Pathobiology of the aggressive and highly aggressive non-Hodgkin's lymphomas&lt;/ref&gt; It is typically diagnosed between the ages of 25 and 40 years. It is twice as common in women as in men. Of all cancers involving the same class of blood cell, 31% of cases are DLBL.&lt;ref name="isbn0-7817-5007-5"&gt;&lt;/ref&gt;

Classification
Two&lt;ref name="Turgeon"&gt;&lt;/ref&gt; or three&lt;ref name="pmid18765795"&gt;&lt;/ref&gt; 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.&lt;ref name="pmid17448534"&gt;&lt;/ref&gt;
 * 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:&lt;ref&gt;"Diffuse large cell lymphoma" at Atlas of Genetics and Cytogenetics in Oncology and Haematology&lt;/ref&gt;


 * t(14;18)(q32;q21) with BCL2-rearrangement.
 * t(3;Var)(q27;Var) with BCL6-rearrangement. These are common translocations.&lt;ref name="pmid16075463"&gt;&lt;/ref&gt;
 * t(8;14)(q24;q32) with MYC rearrangements.
 * and other less characteristic anomalies.

Histomorphology
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.

Treatment
Standard treatment is CHOP. An expanded protocol, called CHOP-R, has improved survival&lt;ref name="pmid17105812"&gt;&lt;/ref&gt; and rates of complete responses for DLBL patients, particularly elderly patients.&lt;ref name="Turgeon"/&gt; 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.

Prognosis
The germinal center subtype has the best prognosis, with 60% of treated patients surviving more than five years.&lt;ref name="Turgeon"/&gt;