Primary testicular diffuse large B-cell lymphoma
Primary testicular diffuse large B-cell lymphoma (PT-DLBCL), also termed testicular diffuse large B-cell lymphoma and diffuse large B-cell lymphoma of the testes, is a variant of the Diffuse large B-cell lymphomas (DLBCL). DLBCL are a large and diverse group of B-cell malignancies with the great majority (-85%) being typed as diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS). PT-DLBCL is a variant of DLBCL, NOS that involves one or, in uncommon cases, both testicles. Other variants and subtypes of DLBCL may involve the testes by spreading to them from their primary sites of origin in other tissues. PT-DLBCL differs from these other DLBCL in that it begins in the testes and then may spread to other sites.

The B-cells in PT-DLBCL are malignant lymphocytes that normally function in the humoral immunity component of the adaptive immune system by secreting antibodies that, for example, bind to and neutralize invasive pathogens. In ~75% of PT-DLBCL cases these malignant B-cells are termed "activated B-cells" to distinguish them from "germinal center B-cells." While DLBCL may involve either type of B-cell, the various forms and subtypes of the DLBCL that involve activated B-cells are more aggressive and may require different therapies than those involving germinal center B-cells. 
Lymphomas that begin in the testes, i.e. primary testicular lymphomas (PTL), are rare forms of lymphoma that represent 1-2% of all non-Hodgkins lymphomas and 5% of all testicular malignancies. PT-DLBCL is by far the most common form of PTL, accounting for >85% all PTL cases. Other forms of PTL include testicular mantle cell lymphoma, extranodal marginal zone B cell lymphoma, extranodal NK/T-cell lymphoma, nasal type, peripheral T-cell lymphoma, activin receptor-like kinase-1–negative anaplastic large cell lymphoma, and pediatric-type follicular lymphoma. Some European investigators have combined PT-DLBCL and most of the latter lymphomas into a lymphoma group termed "non-Hodgkin's primitive lymphoma of the testes".

All forms of PTL except the pediatric-type follicular lymphoma are highly aggressive malignancies PT-DLBCL is no exception to this rule: it begins in a testis, often spreads to the contralateral (i.e. uninvolved) testis as well as to the central nervous system and other sites, and commonly recurs following its treatment. In consequence, the disease has had a 5-year cause-specific survival of only ~60%. Addition of the immunotherapeutic drug, rituximab, to standard chemotherapy protocols has somewhat improved the treatment of most cases of this disease. In addition, clinical trials are testing new drugs for preventing relapses in, as well as treating, PT-DLBCL.
Q2626074
Diffuse large B-cell lymphoma
Concept
Q188930
B-cell
Concept
None
diffuse large B-cell lymphoma, not otherwise specified
UNK
Q9384
testicles
Concept
Q715347
lymphocytes
Concept
Q1142875
humoral immunity
Concept
Q1645075
adaptive immune system
Concept
Q79460
antibodies
Concept
Q170065
pathogen
Concept
Q208414
Lymphomas
Concept
Q1138590
non-Hodgkins lymphoma
Concept
Q268713
mantle cell lymphoma
Concept
Q591256
extranodal marginal zone B cell lymphoma
Concept
Q4763254
extranodal NK/T-cell lymphoma, nasal type
Concept
Q7168693
peripheral T-cell lymphoma
Concept
None
activin receptor-like kinase-1–negative anaplastic large cell lymphoma
UNK
Q85792633
pediatric-type follicular lymphoma
Concept
Q47273
central nervous system
Concept
None
cause-specific survival
UNK
Q1427096
immunotherapeutic
Concept
Q412323
rituximab
Concept
Q974135
chemotherapy
Concept
Q30612
clinical trials
Concept
Q85794495
Primary testicular diffuse large B-cell lymphoma
UNK
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