1. Multicentric Castleman Disease: unusual clinical presentations and outcome in 6 recent cases Ch. Martin, D. Konopnicki, S. De Wit, N. Clumeck Saint-Pierre University Hospital, Brussels, Belgium. E-mail : maladiesinfectieuses@stpierre-bru.beBackground Multicentric Castleman Disease (MCD) is a rare HIV-associated disease described mostly in caucasian homosexual men not treated for HIV. The precise incidence is unknown but some reports suggest a recent increasing possibly due to better diagnosis and awareness of clinicians. Clinical presentation of MCD is polymorphic and sometimes fulminant. It is a polyclonal lymphoproliferative disorder but monoclonal plasmablastic microlymphomas are often described in biopsied lymph nodes and risk for lymphomatous plasmablastic transformation is important (Oksenhendler 2002). Methods We describe 6 HIV-positive patients with MCD +/- plasmablastic lymphoma transformation diagnosed and managed in our institution during the last 3 years (2008-2011) and compare our data’s with series of MCD described in the literature. Results At time of MCD diagnosis: RangeMeanMedian Age (years) 33-5240.338.5 Duration of HIV infection (months) 12-6726.521 Nadir CD4 count (cells/mm³) 46-706236160 CD4 (cells/mm³) 46-1010305195 HIV-RNA (cp/ml) all patients (n=6) all patients (n=6) patients already on HAART (n=4) patients already on HAART (n=4) 0-731,000 <20 126,805 <20 0 <20 Duration of HAART (n=4) (months) 10-2110.611 Conclusion We describe unusual presentation and outcome of Multicentric Castleman Disease :   Epidemiology: 33% in heterosexual African women and 66% in patients with undetectable HIV-RNA under HAART.  Presentation: plasmablastic lymphoma transformation was more frequent than reported in literature (66% vs 6.8% in Mylona 2008).  Prognosis was better in patients with lymphoma treated by R-CHOP (4/4 alive in complete remission) than in patients without lymphoma (2/2 deaths). We suggest to implement a Belgian protocol to collect MCD characteristics from the post-HAART era and to treat MCD following recent recommendations. 6 patients 4 homosexuel men 2 african heterosexuel women 2 african heterosexuel women MCD 1 fulminant death Post-mortem diagn. MCD 1 fulminant death Post-mortem diagn. 3 MCD with lymphomatous transformation 3 MCD with lymphomatous transformation 1 MCD with lymphomatous transformation 1 MCD with lymphomatous transformation 1 pulmonary MCD 1 pulmonary MCD 3 R-CHOP +/- valganciclovir 3 CR alive: FU 29-16-16 months 3 R-CHOP +/- valganciclovir 3 CR alive: FU 29-16-16 months 1 R-CHOP 1 CR alive: FU 18 months 1 R-CHOP 1 CR alive: FU 18 months 1 R-CHOP then Etoposide PR Death at13 months. 1 R-CHOP then Etoposide PR Death at13 months. Symptoms:  Lymph nodes 2/6  Anaemia with irregular antibody 3/6  B symptoms 4/6  Respiratory insufficiency 1/6  Palatin mass 1/6 Association with Kaposi Sarcoma 3/6 (2 stomach, 3 lymph node capsule) in plasmablastic lymphomaTransformation in plasmablastic lymphoma 4/6 Bone marrow: No invasion 5/6 B monoclonality 1/6 MCD flare-up after HAART initiation1/2 Mortality 2/6 (33%) Unusual findings: 2/6 heterosexual African women, 4/6 HIV-RNA<20 under HAART 1/2 flare-up of symptoms after HAART initiation, coexistent lymphoma 66%, 4/4 lymphomas treated with R-CHOP alive. R-CHOP= Rituximab and CHOP. CR = Complete remission. PR= Partial remission