Kicking up a cytokine storm: an unusual presentation of Castleman’s disease

Castleman’s disease (CD) is a rare lymphoproliferative disorder that can be separated into localised disease and multicentric Castleman’s disease (MCD). Kaposi’s sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus-8 (HHV-8) is the causal agent for Kaposi’s sarcoma (KS) and MCD in human immunodeficiency virus (HIV)-infected patients. This virus encodes a homologue of interleukin 6 (vIL-6), which may mediate some systemic features of MCD. A 58-year-old man presented to the infectious disease department with a three-day history of dyspnoea, fever, and cough. He had a history of HIV and had been on antiretroviral treatment for the previous year. Despite compliance, his CD4 count had dropped and he was found to have widespread lymphadenopathy and pancytopaenia on admission. Biopsy showed the presence of KS and it was decided to treat him for an ‘MCD-like’ syndrome based on his clinical presentation. The patient responded well to treatment with rituximab, an agent used for MCD, and his haematological profile improved. This case lends support to the theory that some patients with HIV and HHV-8 co-infection, but without MCD, can develop severe systemic inflammatory symptoms associated with elevated levels of HHV-8 vIL-6, IL-6 and HHV-8 viral loads. It additionally illustrates the challenges faced in the diagnosis of this unusual form of MCD in patients with HIV. Most importantly, this case highlights the importance of a thorough history and examination in eliciting the clues to diagnosis in the face of these challenges.