Diagnostic challenge of human herpesvirus 8-associated multicentric Castleman disease in a patient living with HIV disease.

A man in his early 30s presented with a 4-month history of low-grade fever and chronic dry cough. Three months before admission, he developed persistent low-grade fever, rash and bilateral cervical lymphadenopathy. He was diagnosed with HIV infection and started on tenofovir/lamivudine/dolutegravir. Two weeks before admission, he developed right-sided pleuritic chest pain. Chest CT revealed bilateral pleural effusions and generalised lymphadenopathy involving the lower cervical, mediastinal and axillary regions. An excisional biopsy of a right lower cervical lymph node demonstrated hyaline-vascular architecture, including 'lollipop' lesions and onion-skinning of the mantle zones. Immunohistochemistry showed human herpesvirus 8 (HHV-8)-positive plasmacytoid cells within the mantle zones, without malignant features, consistent with HHV-8-associated multicentric Castleman disease (MCD). The patient continued antiretroviral therapy and received rituximab 375 mg/m² every week for four cycles. He achieved complete resolution of the pleural effusions. This case illustrates the variable clinical presentation of HHV-8-associated MCD in a patient living with HIV.