Primary effusion lymphoma

Primary effusion lymphoma (PEL) is a B-cell lymphoma, presenting with a malignant effusion without a tumor mass.

Presentation
PEL is unusual in that the majority of cases arise in body cavities, such as the pleural space or the pericardium; another name for PEL is "body cavity lymphoma".

The immunophenotype : CD45+ (95%), CD20-, CD79a-, PAX5-, CD30+, CD38+, CD138+ and EMA+. Staining the nucleus for HHV-8 LANA may be helpful.

Causes
PEL most commonly arises in patients with underlying immunodeficiency, such as AIDS. PEL is caused by Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8 (HHV-8). In most cases, the lymphoma cells are also infected with Epstein Barr virus (EBV). In the cases, the World Health Organization (2016) classifies the disease as one of the Epstein-Barr virus-associated lymphoproliferative diseases, i.e. EBV+ primary effusion lymphoma. EBV is found in the malignant HHV8+ B cells in ~70% of PEL patients. However, a role for this virus in the development of PEL is not supported since HHV8 appears to drive the development and progression of the disease. PEL condition can exist in the absence of HHV-8 and HIV, though this is rare.

Prognosis
It is generally resistant to cancer chemotherapy drugs that are active against other lymphomas, and carries a poor prognosis.

Sirolimus has been proposed as a treatment option.

History
It was recognized as a unique type of lymphoma only after the discovery of KSHV in 1994.

See also
 List of hematologic conditions

References

External links 

Category:Lymphoma
Category:Epstein–Barr virus-associated diseases
Category:Infectious causes of cancer