KSHV/HHV8-negative effusion-based lymphoma, a distinct entity associated with fluid overload states

Area of Science:

• Hematology
• Oncology
• Virology

Background:

• Primary effusion lymphoma (PEL) is defined as Human Herpesvirus-8 (HHV8)-positive effusion-based lymphoma.
• Kaposi sarcoma herpesvirus (KSHV)/HHV8-negative effusion-based lymphomas (EBLs) have been misclassified as PEL-like lymphomas.
• This study reviews KSHV/HHV8-negative EBLs, highlighting their distinct clinical and pathological features.

Observation:

• Patients with KSHV/HHV8-negative EBLs are typically older, human immunodeficiency virus (HIV)-negative, and not immunosuppressed.
• Hepatitis C positivity is common, and an underlying condition leading to fluid overload is frequently observed.
• Lymphoma cells express pan-B-cell antigens (86.7%) and CD20 (71.1%), with a germinal center B-cell or mixed signature.

Findings:

• KSHV/HHV8-negative EBL is a distinct entity from PEL, despite cytomorphological similarities.
• Epstein-Barr virus (EBV) is positive in nearly 30% of cases; rare T-cell lymphomas are also noted.
• Clinical outcomes and response to treatment, including aspiration, are more favorable than in PEL.

Implications:

• KSHV/HHV8-negative EBL should be recognized as a distinct clinicopathological entity.
• Association with fluid overload states suggests potential underlying mechanisms or risk factors.
• Distinguishing KSHV/HHV8-negative EBL from PEL is crucial for accurate diagnosis and treatment planning.