Despite the movement to eradicate anecdotes from the medical literature, this edition of the Journal of HIV Therapy contains fascinating case reports and series. In this era of evidence-based medicine, a good example of the utility of such individualised descriptions can be derived from the history of multicentric Castleman's disease (MCD). After years of case reports and small series, three publications this year now provide us with timely data demonstrating the safety and efficacy of an anti-CD20 monoclonal antibody, rituximab, in patients with HIV-associated MCD. As well as impressive data derived from cohorts of patients with a rare and difficult-to-diagnose disease, it is gratifying to note that the current evidence for treatment of MCD is based almost entirely on the HIV experience.
The first description of MCD appeared in 1954, as a case record of the Massachusetts General Hospital . Two years later, Benjamin Castleman, the pathologist at Massachusetts General Hospital, described 13 cases of localised asymptomatic mediastinal masses demonstrating lymph node hyperplasia resembling thymoma . It was thought to be a non-neoplastic polyclonal lymphoproliferative disease or 'pre-lymphoma'. There has been a resurgence of interest secondary to its apparent predilection for HIV-positive individuals although no studies have formally examined its incidence, prevalence or the relative risk associated with immunosuppression. In the context of HIV infection, MCD is an often fatal lymphoproliferative disorder associated with Kaposi's sarcoma-associated herpesvirus (KSHV) infection and many of its clinical attributes are due to overexpression of KSHV gene products pirated from its human host, notably interleukin-6 (IL-6) . The clinical course is characterised by recurrent attacks with systemic symptoms associated with high serum C-reactive protein level and high KSHV viral load in peripheral blood mononuclear cells. Diagnosis is based on pathological examination of lymphadenopathy or spleen showing hyalinised atrophic germinal centres associated with vascular hyperplasia and plasma cell infiltration in the interfollicular area. Kaposi's sarcoma (KS) is often associated with MCD. The clinical course can be self-limited at the onset of the disease, but most patients die with active MCD or evolution towards KSHV-associated non-Hodgkin's lymphoma (NHL) .
Until recently, the treatment of HIV-associated MCD was based on individual...