48-year-old man, diagnosed with HHV-8 positive multicentric Castleman disease (MCD). He was started on etoposide and rituximab and showed a good response with resolution of lymphadenopathy and reduction in splenomegaly.

He was readmitted a year later with generalized lymphadenopathy, splenomegaly, bilateral pleural effusions, ascites, generalized edema, and fever. An excisional biopsy of left cervical lymph node and bone marrow biopsy were performed.

The lymph node morphology showed germinal centers with varied degrees of involution and hyalinization and poorly defined mantle zones. The interfollicular areas were expanded by numerous mature-appearing plasma cell and vascular proliferation. Small aggregates of plasmacytoid immunoblasts /plasmablasts with vesicular chromatin and prominent nucleoli were present in the germinal centers, mantle zones and interfollicular areas. No large aggregates or sheets of plasmablasts were identified. The subcapsular areas also showed presence of Kaposi Sarcoma.

The bone marrow morphology showed hyper cellular bone marrow for age (80% cellularity) with HIV-infection associated changes, including dysplastic left-shifted trilineage hematopoiesis, multiple large lymphoid aggregates and rare scattered plasmablasts.