The AIDS was first described in 1981, and the first definitions included certain opportunistic infections, Kaposi sarcoma, and central nervous system (CNS) lymphomas. In 1984, a multicenter study described the clinical spectrum of non-Hodgkin lymphomas (NHLs) in the populations at risk for AIDS. In 1985 and 1987, the Centers for Disease Control and Prevention (CDC) revised the definition of AIDS to include human immunodeficiency virus (HIV)-infected patients who had aggressive B-cell NHL. The incidence of NHL has increased in an almost parallel course with the AIDS epidemic and accounts for 2% to 3% of newly diagnosed AIDS cases.
Lymphoma is cancer that begins in infection-fighting cells of the immune system, called lymphocytes. These cells are in the lymph nodes, spleen, thymus, bone marrow, and other parts of the body. When you have lymphoma, lymphocytes change and grow out of control.
There are two main types of lymphoma:
Non-Hodgkin: Most people with lymphoma have this type.
Non-Hodgkin and Hodgkin lymphoma each affect a different kind of lymphocyte. Every type of lymphoma grows at a different rate...
Pathologically, AIDS-related lymphomas are comprised of a narrow spectrum of histologic types consisting almost exclusively of B-cell tumors of aggressive type. These include the following:
Diffuse large B-cell lymphoma.
B-cell immunoblastic lymphoma.
Small noncleaved lymphoma, either Burkitt or Burkitt-like.
The HIV-associated lymphomas can be categorized into the following:
Aggressive B-cell lymphoma.
Primary central nervous system lymphoma (PCNSL), which represents 20% of all NHL cases in AIDS patients.
Primary effusion lymphoma.
Plasmablastic multicentric Castleman disease.
Primary effusion lymphoma
Primary effusion lymphoma has been associated with Kaposi sarcoma-associated herpes-virus/human herpes virus type-8 (KSHV/HHV-8).[3,4] Primary effusion lymphoma presents as a liquid phase spreading along serous membranes in the absence of masses or adenopathy. In addition to HHV-8, many cases are also associated with Epstein-Barr virus. Extension of lymphoma from the effusion to underlying tissue may occur. Plasmablastic multicentric Castleman disease is also associated with a coinfection of KSHV/HHV-8 and HIV.[5,6] Patients typically present with fever, night sweats, weight loss, lymphadenopathy, and hepatosplenomegaly. Patients may progress to primary effusion lymphoma or to plasmablastic or anaplastic large cell lymphoma. Anecdotal responses to rituximab, an anti-CD20 monoclonal antibody, have been reported.[Level of evidence: 3iiiDiv]
Incidence and Prevention
An international database of 48,000 HIV-seropositive individuals from the United States, Europe, and Australia found a 42% decline in the incidence of NHLs from 1997 to 1999 compared with 1992 to 1996, both for PCNSL and for systemic lymphoma. The introduction of highly active antiretroviral therapy (HAART) is the proposed explanation for this decline. The diagnosis of AIDS precedes the onset of NHL in approximately 57% of the patients, but in 30% of the patients the diagnosis of AIDS is made at the time of the diagnosis of NHL and HIV positivity. The geographic distribution of these lymphomas is also similar to the geographic spread of AIDS. Unlike Kaposi sarcoma, which has a predilection for homosexual men and appears to be on the decline in incidence, all risk groups appear to have an excess number of NHLs; these risk groups include intravenous drug users and children of HIV-positive individuals.