ABSTRACT
Immunocompromised patients are susceptible to the development of lymphoid neoplasms within the central nervous system (CNS). The patients at risk of these malignancies include those with congenital immunodeficiencies (e.g., Wiskott-Aldrich syndrome) as well as those with acquired immunodeficiency. Acquired immunodeficiency may be the result of illness, e.g., lupus, or infection, e.g., acquired immunodeficiency syndrome (AIDS), or iatrogenic immunosuppression, e.g., after transplantation. Two specific groups of patients are susceptible to these lymphoid malignancies: patients with AIDS and those who have received solid-organ transplants. In both these groups of patients the lymphoid proliferations are thought to be due to an Epstein-Barr virus (EBV)-induced B-cell proliferation, which is unopposed by the suppressed T cells [suppressed either as a result of immunosuppressive drugs or human immunodeficiency virus (HIV) infection]. Transplant patients most commonly develop post-transplant lymphoproliferative disorders within the first two years after transplantation. The lymphoid proliferations in these patients have some similarities in imaging appearances, which is not unexpected given their identical pathogenesis. These appearances are often distinct from those of primary central nervous system lymphoma (PCNSL) in the immunocompetent patient. There does not seem to be any documented increased risk of primary glial neoplasms of the CNS in these patients.
