Six patients have been observed which exhibited the features of the so called immunoblastic lymphadenopathy. The histological and clinical findings allow to distinguish the disease from both the malignant lymphomas and other forms of benign pseudolymphomas. The most important clinical features are severe general symptoms, generalised lymphadenopathy, hepatosplenomegaly, skin rash and a variety of abnormal reactions in the B-cell system such as hypergammaglobulinaemia, a transient positive Coombs test and the appearance of plasma cells in the peripheral blood. Evidence for a neoplastic nature of the disease is lacking. Nevertheless, the course of the disease may be progressive and fatal, but spontaneous remissions and subsequent relapses have also been essential part of the therapeutic strategy. Immunosupressants such as corticosteroids may have a positive effect in cases with immunological complications.