Malignant tumors and AIDS.

One in six patients with acquired immunodeficiency syndrome (AIDS) both in the USA and Europe develop malignancies, in particular Kaposi's sarcoma (KS) and non-Hodgkin's lymphoma (NHL). After an initial rapid increase, the proportion of AIDS patients with KS steadily declined in the USA and in Europe, while the proportion of AIDS-NHL has been stable during the last decade in the USA and Europe. Human immunodeficiency virus (HIV) infected patients are living longer due to advances in antiretroviral therapy and treatment of prophylaxis against opportunistic infections, yet because of their immunodeficiency they are at high risk for 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 behavior and therapeutical response distinguish tumors in patients with HIV infection from those without. 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, ie, blastic and anaplastic cell lymphomas, has been formulated. The treatment of HIV-related neoplasms is controversial as it is not clear whether conventional therapy, particularly chemotherapy, is able to modify the natural history of these malignancies in the HIV setting. Moreover the treatment of HIV-related tumors presents several problems due to the aggressive behaviors of tumors and because of immunosuppressive chemotherapy employed in patients with immunodeficiency. This paper reviews the most relevant data on the epidemiology, pathology and treatment of malignant tumors in patients with HIV infection.