Interleukin-6 and Castleman’s Disease

In 1956, Castleman et al. reported 13 patients who had localized mediastinal lymph node hyperplasia resembling thymoma (1). The characteristic features of the hyperplastic lymph nodes were follicular hyperplasia with a large germinal center penetrated by branching hyaline blood vessels and proliferation of hyaline capillaries with endothelial hyperplasia in the interfollicular areas. Thereafter, Flendrig et al. and Keller et al. independently reported another morphologic type of the benign giant lymph node characterized by hyperplastic germinal centers and intervening sheets of plasma cells (2,3). The former is referred to as the hyaline-vascular type (HV type) and the latter as the plasma cell type (PC type) of Castleman’s disease.