Non-Hodgkin’s Lymphoma

Abstract Non-Hodgkin’s lymphoma is defined as all lymphomas other than Hodgkin’s disease. Among HIV-infected individuals, the incidence of non-Hodgkin’s lymphoma is increased approximately fivefold. Overall, approximately 3 to 10 percent of HIV- infected individuals develop some type of non-Hodgkin’s lymphoma. All HIV-infected persons appear to be at increased risk for developing lymphomas, regardless of their risk factor for acquiring HIV. Recognized by the Centers for Disease Control and Prevention as AIDS-defining diagnoses, primary central nervous system (CNS) lymphoma and systemic high-grade lymphoma constitute about 3 percent of AIDS-defining conditions. Lymphomas are characterized by their cell type (B cell or T cell), histologic features, and natural history (low grade, intermediate grade, or high grade). HIV-related lymphomas are predominantly B-cell tumors, with 75 to 80 percent classified as high grade, exhibiting either immunoblastic or small noncleaved cell (Burkitt’s and non- Burkitt’s) histology. By comparison, high-grade histology is found in only 10 to 15 percent of non-HIV-related lymphomas in a comparable age group. Diffuse large cell lymphoma is the other major histologic type of HIV-related lymphoma; although it is classified as intermediate grade, it behaves more agressively (like a high-grade lymphoma) in HIV-infected individuals.