Human immunodeficiency virus (HIV) has a strong tropism for lymphoid tissues, particularly CD4+ T lymphocytes, monocytes, and dendritic cells. In acute HIV infection, the virus migrates to lymphoid organs, where it causes reactive lymphadenitis. Chronic HIV infection is characterized by impairment and destruction of CD4+ T cells and dendritic cells, which leads to a progressive alteration in lymphoid tissue architecture. Different morphologic patterns of lymph node architecture correlate with the evolutionary stages of HIV disease. Three histologic patterns (A, B, and C) 1.2 have been described: