Concurrence of localized Castleman's disease and peripheral small B-Lymphocytic lymphoma within the same lymph node

Castleman's disease, also known as benign giant lymph node hyperplasia, is a lymphoproliferative disorder which can occur either in a localized or multicentric form. The latter is characterized by the development of malignant lymphoma, Kaposi's sarcoma or carcinoma in 32% of cases. By contrast, localized Castleman's disease has exceptionally been reported in association with non-Hodgkin's lymphoma and - to the best of our knowledge - never at the same anatomic site. Here we describe the occurrence in the same lymph node of localized Castleman's disease (with monotypic plasma cell component) and an apparently unrelated peripheral small B-lymphocytic lymphoma.