a syndrome characterized by reactive hyperplasia of lymph nodes (of at least 1 month's duration and at two different body sites, not including the inguinal area) in patients infected with the human immunodeficiency virus. The lymph node lesions progress from benign reactive hyperplasia through a stage of mixed follicular hyperplasia to follicular involution with lymphocyte depletion. Many go on to a malignant non-Hodgkin lymphoma.