Primary Effusion Lymphoma : Differential

Comments:
Differential Diagnosis: Primary effusion lymphoma (PEL) should be differentiated from other rare effusion-based lymphomas that are HHV8-negative. Pleural cavity-based lymphomas can occur after long-standing suppurative inflammation (diffuse large B-cell lymphoma associated with chronic inflammation), e.g. pyothorax-associated lymphoma; following artificial pneumothorax; and following tuberculous pleuritis. They are all B-cell lymphomas with plasmocytoid differentiation and associated with EBV.

Older individuals with chronic inflammation or fluid imbalance states (e.g. cirrhosis) may develop peritoneal cavity-based lymphomas unassociated with HIV or HHV8 infection.

Rare cases of Burkitt lymphoma may involve body cavities in HIV patients; however, these cases are HHV8-negative and have MYC gene rearrangement.

The image shows intravascular form of primary effusion lymphoma that was initially confined to dermal vessels and then presented with pleural effusion.

Image courtesy of: Genevieve Crane, MD, PhD.