<unk>  (DLBCL-CI) is a subtype of the<unk>  large B-cell<unk> s and a rare form of the Epstein–Barr virus-associated lymphoproliferative diseases, i.e. conditions in which lymphocytes infected with the Epstein-Barr virus (EBV) proliferate excessively in one or more tissues. EBV infects ~95% of the world's population to cause no symptoms, minor non-specific symptoms, or infectious mononucleosis. The virus then enters a latency phase in which the infected individual becomes a lifetime asymptomatic carrier of the virus. Some weeks, months, years, or decades thereafter, a very small fraction of these carriers, particularly those with an immunodeficiency, develop any one of various EBV-associated benign or malignant diseases. The EBV-associated diseases include: 1) some cases of non-lymphoproliferative disorders such as the Alice in Wonderland syndrome, cerebellar ataxia, particularly childhood cases of this disorder, and two autoimmune diseases, multiple sclerosis and systemic lupus erythematosis; 2) non-lymphoid cancers such as EBV+ gastric cancer, most if not all cases of nasopharyngeal cancer, and some cases of soft tissue sarcoma and leiomyosarcoma; and 3) Epstein-Barr virus-associated lymphoproliferative diseases such as<unk>  active EBV infection, EBV+ hemophagocytic lymphohistiocytosis, EBV+ Burkitt<unk> , EBV+ Hodgkin<unk> , and the EBV+<unk>  large B-cell<unk> s which include as a subtype, DLBCL-CI. DLBCL-CI is a highly aggressive malignancy that most commonly afflicts elderly males. In this disease, EBV-infected B-cell lymphocytes located in sites of<unk><unk>  that are walled off from the immune system proliferate excessively, acquire pro-malignant gene changes, and eventually form a tumor mass. The historically most common form of DLBCL-CI, often termed pyothorax-associated<unk>  (PAL), exemplifies this disease. PAL develops in grossly inflamed pleural cavities may years after a pneumothorax is medically induced to collapse a lobe or entire lung in order to treat pleurisy caused by an otherwise uncontrollable inflammatory condition, usually (i.e. ~80% of all PAT cases) pulmonary tuberculosis. The pleural cavity and the inflammatory pus within it are thought to protect the EBV-infected B-cells from immune attack. Given the decline in the occurrence of<unk>  pleural tuberculosis and the virtual abandonment of therapeutic pneumothorax to treat<unk>  pleural<unk> , PAT is rarely encountered today. Currently, DLBCL-CI is diagnosed in other sites of<unk><unk>  that are or appear to be sequestered from the immune system such as infected joints and bones or areas in and around foreign bodies. In 2017, the World Health Organization provisionally included Fibrin-associated<unk>  large B cell<unk>  (FA-DLBCL) as a form of DLBCL-CI. Similar to DLBCL-CI, FA-DLBCL is a<unk>  large B-cell<unk>  that arises in immunologically sequestered sites (e.g. body cavities, foreign bodies). Unlike DLBCL-CI, however, FA-DLBCL most commonly develops in sites where fibrin, a breakdown product of the blood clotting factor, fibrinogen, forms and deposits on the abnormal tissues in body cavities or around foreign bodies. FA-DLBCL also differs from DLBCLCI in that it usually presents as infiltrates rather than tumors and is a far less aggressive and in many cases a relatively benign disease. Here, it is considered in the differential diagnosis of DLBCL-CI and more fully described elsewhere (see fibrin-associated<unk>  large B-cell<unk> .
Diffuse large B-cell lymphoma associated with chronic inflammation
Large B-cell lymphoma arising in HHV8-associated multicentric Castleman's disease
Splenic lymphoma with villous lymphocytes
Germinal center B-cell like diffuse large B-cell lymphoma
Chronic multifocal Langerhans cell histiocytosis
Thymoma-associated multiorgan autoimmunity
Epstein–Barr virus positive diffuse large B-cell lymphoma, not otherwise specified
Lymphoid neoplasms with plasmablastic differentiation