histiocytic necrotizing lymphadenitis, or kikuchi's lymphadenitis (kl), is an unusual form of lymphadenitis, generally with self-limited clinical course. kl has been reported in rare patients infected with the human immunodeficiency virus (hiv). pathogenesis of the lesion is probably related to an impaired immune function. the purpose of the present article is to report on one case in which kl was diagnosed in an hiv-infected patient. histomorphology and immunophenotype were similar to previous reports, but a focus of activated cd30+ macrophages was seen, what might be due to the immunological status of the patient. ebv was not detected on the sections using the in situ hybridization technique. although rare, the occurrence of kl in hiv-infected subjects must be emphasized, because of the potential misdiagnosis of malignancy, especially in the presence of cd30+ cells.