Multicentric Castleman's Disease and Kaposi's Sarcoma in a HIV-Positive Patient on Highly Active Antiretroviral Therapy.

Castleman's disease is a group of rare lymphoproliferative disorders. The plasmablastic multicentric Castleman's disease is frequently discovered in HIV-infected individuals in association with Kaposi sarcoma (HHV-8). Thirty-five year old male presented to our care with the main compliant of severe back pain for one week. His past medical problems include acquired immune deficiency syndrome diagnosed 12 years prior and Kaposi sarcoma, currently on highly active antiretroviral therapy (HAART). Radiographic imaging revealed hepatomegaly and diffuse lymphadenopathy. The HIV viral load was <20 polymerase chain reaction copies/mL, absolute CD4 count was 453 cells/mcL (490-1740 cells/mcL) and CD8 count was 4142 cells/mcL (180-1170 cells/ mcL). Excisional biopsy of the left supraclavicular lymph node was performed with pathological findings of HHV8+ Kaposi sarcoma in the background of multicentric Castleman's disease (plasmacytic variant). No evidence of transformation into large B-cell or plasmablastic lymphoma was noted. He was discharged on HAART and follow up to receive chemotherapy with cyclophosphamide, adriamycin, vincristine plus prednisone was started and rituximab plus prophylaxis for pneumocystis carinii. Multicentric Castleman's disease has become more relevant in recent years due to its association with HIV and HHV-8 (Kaposi sarcoma) and its potential to progress into plasmablastic B-cell lymphoma. The progression of MCD to B-cell lymphoma is a concern, especially in patients with HIV infection because it precludes the worst outcome and a high mortality, despite treatment. The most intriguing part of this case is that MCD occurred in a HIV-positive on HAART. This case signals a warning that a high suspicion for MCD can be justified even in those HIV-positive patients on HAART because the possibly of progression to plasmablastic B-cell lymphoma.