A CT scan showed hepato-splenomegaly and gross lymphadenopathy involving the thorax, abdomen and pelvis ( Figure 1 ). Inguinal lymph node excision biopsy confirmed the clinical suspicion of Multi-centric Castleman's disease (MCD) (Figure 2 ). Rituximab (375 mg/m 2 ) together with hydrocortisone and rasburicase, was administered as specific treatment. She developed rapidly progressive metabolic acidosis, oliguria, and rising serum creatinine and was admitted to the ICU for haemofiltration. Antiretroviral therapy was continued on the ICU with ritonavir-boosted lopinavir and saquinavir. Abacavir and lamivudine, which the patient was already taking, were stopped because of their association with lactic acidosis and hepatic steatosis.