Malignant lymphomas in patients with HIV infection.

During the last two decades, the occurrence of non-Hodgkin's lymphoma (NHLs) has been increasing both in the general population, in which their incidence doubled, and in people with human immunodeficiency virus (HIV) infection, in whom a 100-fold increase has been observed since the onset of the AIDS epidemic. HIV infected patients are living longer owing to advances in antiretroviral therapy and treatment of prophylaxis against opportunistic infections but because of their immunodeficiency they are at high risk of cancers, especially NHL. The natural history of cancers in patients with HIV infection differs from that of the general population. Unusual aspects of tumor localization, growth behaviour and therapeutical response, distinguish tumors in patients with from those without HIV infection. The pathologic and virological aspects of HIV-related tumors are peculiar and a pathological classification of HIV associated systemic lymphomas based on the morphological features of the two main types, i.e. blastic and anaplastic cell lymphomas has been formulated. The treatment of HIV-related neoplasms is controversial as it is not clear whether conventional therapy and in particular chemotherapy is able to modify the natural history of these malignancies in HIV setting. Moreover the treatment of HIV-related tumors presents several problems, due to the aggressive behaviours of tumors and because of immunosuppressive chemotherapy employed in patients with immunodeficiency.