Lymphadenopathy in HIV infection: histological classification and staging.

The histological alterations seen in HIV-related lymphadenopathy have been described with different terms by different authors. In order to facilitate comparisons of results from various laboratories, a group of pathologists of the European Lymphoma Study Group (later the European Association for Haematopathology) have proposed a histological classification for the evaluation of HIV related lymphadenopathy. Most observers agree that the morphological and immunohistochemical alterations in the follicles (germinal centres) are the most conspicuous and earliest changes seen. The follicular alterations were therefore used as the basis for the proposed classification. In addition, some features occasionally seen were also included, i.e. angioimmunoblastic hyperplasia, multicentric Castleman-like lesions, and vascular lesions, especially pretumorous and tumorous stages of Kaposi's sarcoma. The proposed classification was used by the members of the group of a collection of lymph nodes compiled from the various centres. The classification was shown to be reproducible and to have clinical relevance in staging of the patients. The prognostic relevance as to the survival of the patients has to be further substantiated by follow-up studies. The proposed classification offers a common terminology for the alterations previously described by different terms by various authors.