HIV-negative KSHV/HHV8-associated multicentric Castleman disease with concurrent Kaposi sarcoma and POEMS-like...

Area of Science:

• Hematology
• Oncology
• Infectious Diseases

Background:

• Castleman disease (CD) is a lymphoproliferative disorder with unicentric and multicentric forms.
• Multicentric CD (MCD) is classified into idiopathic MCD (iMCD), POEMS-associated MCD, and Kaposi sarcoma-associated herpesvirus (KSHV/HHV-8)-associated MCD, often presenting with systemic inflammation.
• KSHV/HHV-8-associated MCD is typically observed in HIV-positive individuals but can rarely occur in HIV-negative patients.

Purpose of the Study:

• To report a unique case of KSHV/HHV-8-associated MCD in an HIV-negative patient.
• To highlight the diagnostic challenges posed by concurrent Kaposi sarcoma and POEMS-like features in this rare presentation.
• To discuss the treatment and outcome of this complex case.

Main Methods:

• Case report of a 65-year-old HIV-negative woman diagnosed with mixed-type KSHV/HHV-8-associated MCD.
• Clinical presentation included generalized lymphadenopathy, splenomegaly, cytopenias, hypercalcemia, and monoclonal IgG lambda gammopathy.
• Diagnostic workup involved PET-CT, bone marrow examination, and lymph node biopsy confirming HHV-8 positivity and Kaposi sarcoma.

Main Results:

• The patient exhibited mixed-type KSHV/HHV-8-associated MCD with Kaposi sarcoma and POEMS-like clinical features.
• Diagnostic findings included widespread hypermetabolic lymphadenopathy, a sclerotic bone lesion, and HHV-8 DNA positivity.
• Bone marrow showed normocellularity with polytypic plasma cell proliferation.

Conclusions:

• KSHV/HHV-8-associated MCD can occur in HIV-negative individuals, presenting a diagnostic challenge.
• Concurrent Kaposi sarcoma and POEMS-like manifestations can occur in HIV-negative KSHV/HHV-8-associated MCD.
• The patient achieved a significant clinical and hematologic response to treatment with daratumumab, bortezomib, cyclophosphamide, and dexamethasone.