Atypical Lymphoproliferative Diseases.

This review addresses the clinical presentation, pathology, and therapy of several uncommon lymphoid proliferations. Because these lymphoproliferations span the characteristics of reactive polymorphous proliferations to clonal malignant neoplasms, they are often difficult to diagnose and treat effectively. In Section I, Dr. Greiner describes the pathology of the spectrum of atypical lymphoid disorders including Castleman's disease, angioimmunoblastic lymphadenopathy, lymphadenopathy in autoimmune diseases, posttransplant lymphoproliferative disorders, and X-linked lymphoproliferative disorder. The relationship to Epstein-Barr virus (EBV) and human herpsesvirus-8 (HHV-8) is discussed, and molecular diagnostic assays and principles for obtaining proper diagnostic evaluation are emphasized. In Section II, Dr. Armitage presents a practical approach to the management of Castleman's disease. The discussion includes the importance of confirmation of the histological diagnosis and careful staging evaluation, therapeutic options, and the increased risks for infection and lymphoma. The appropriate roles of surgical excision, corticosteroids, and combination chemotherapy are addressed along with alternative strategies such as anti-interleukin-6 and bone marrow transplantation. In Section III, Dr. Gross reviews the treatment of EBV-associated lymphoproliferative disorders in primary immunodeficiencies and in post-transplant patients. He gives an update on the recent molecular discoveries in X-linked lymphoproliferative disorder. Preliminary results of a phase II trial of low-dose cyclophosphamide in posttransplant lymphoproliferative disorders and the use of GM-CSF as preemptive therapy are presented.