Primary effusion lymphoma

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Sowminya Arikapudi, M.B,B.S. [2]

Synonyms and keywords: Body cavity lymphoma; PEL

Overview

Primary effusion lymphoma (PEL) is rare subtype of diffuse large B-cell lymphoma (DLBCL). Primary effusion lymphoma is a very fast-growing (aggressive) lymphoma usually confined to pleural, pericardial, peritoneal body cavities, presenting as serous effusions without detectable tumor masses, occurring primarily but not exclusively in HIV-infected patients. Lymphoma cells are found in the fluid in these body cavities. Primary effusion lymphoma is associated with human herpes virus 8 (HHV8) infection and Epstein-Barr virus (EBV) infection. On microscopic histopathological analysis, neoplastic proliferation of large lymphoid cells with round to irregular nuclei, prominent nucleoli, and varying amounts of vacuolated cytoplasm are characteristic findings of primary effusion lymphoma. Primary effusion lymphoma is more commonly observed among young or middle aged patients. Males are more commonly affected with primary effusion lymphoma than females. Symptoms of primary effusion lymphoma may include fever, fatigue, weight loss, night sweats, painless swellings in the neck, axilla, groin, thorax, and abdomen, chest pain, abdomen pain, bones pain, and skin rash. A lymph node biopsy is diagnostic of primary effusion lymphoma. The mainstay of therapy for primary effusion lymphoma is chemotherapy and antiretroviral therapy.

Pathophysiology

• Primary effusion lymphoma is associated with human herpes virus 8 (HHV8) infection and Epstein-Barr virus (EBV) infection.
• Primary effusion lymphoma most often occurs in people with weakened immune systems, such as those with HIV/AIDS. It can sometimes occur in people who have had organ transplants.
• On microscopic histopathological analysis, neoplastic proliferation of large lymphoid cells with round to irregular nuclei, prominent nucleoli, and varying amounts of vacuolated cytoplasm are characteristic findings of primary effusion lymphoma. There were immunoblastic, plasmablastic and anaplastic variants with bizarre, pleomorphic nuclei.

• 

  At light microscopy, the sample consisted of a frankly neoplastic population provided with plasmablastic and/or anaplastic morphology (Figure 1A), which turned out CD3-, CD20- (Figure 1B), CD79a-, CD45+ (Figure 1C), CD38+, CD30+, IRF4+, LANA-1+ (Figure 1D), EBER+ (Figure 1C inset), and Ki-67>90%. Based on these findings, we made a diagnosis of Primary effusion lymphoma.

Causes

• There are no established causes for primary effusion lymphoma.

Differentiating primary effusion lymphoma from other Diseases

• Primary effusion lymphoma must be differentiated from other diseases such as:

• Plasmablastic lymphoma
• Burkitt lymphoma
• Pyothorax associated lymphoma

Epidemiology and Demographics

Age

• Primary effusion lymphoma is more commonly observed among young or middle aged patients.

Gender

• Males are more commonly affected with primary effusion lymphoma than females.

Risk Factors

• There are no established risk factors for primary effusion lymphoma.

Natural History, Complications and Prognosis

• Primary effusion lymphoma is a very fast-growing (aggressive) lymphoma usually confined to pleural, pericardial, peritoneal body cavities, presenting as serous effusions without detectable tumor masses, occurring primarily but not exclusively in HIV-infected patients.
• Prognosis is generally poor.

Diagnosis

Staging

Staging for primary effusion lymphoma is provided in the following table:

Revised staging system for primary nodal lymphomas (Lugano classification)

Stage	Involvement	Extranodal (E) status
Limited
Stage I	One node or a group of adjacent nodes	Single extranodal lesions without nodal involvement
Stage II	Two or more nodal groups on the same side of the diaphragm	Stage I or II by nodal extent with limited contiguous extranodal involvement
Stage II bulky	II as above with "bulky" disease	Not applicable
Advanced
Stage III	Nodes on both sides of the diaphragm; nodes above the diaphragm with spleen involvement	Not applicable
Stage IV	Additional noncontiguous extralymphatic involvement	Not applicable

Symptoms

• Symptoms of primary effusion lymphoma may include the following:

• Fever
• Fatigue
• Weight loss
• Night sweats
• Painless swellings in the neck, axilla, groin, thorax, and abdomen
• Pain in the chest, abdomen, or bones
• Skin rash

Physical Examination

• Physical examination of primary effusion lymphoma may be remarkable for:

• Fever
• Skin rash
• Cervical lymphadenopathy
• Thoracic masses suggestive of central lymphadenopathy
• Abdominal masses suggestive of central lymphadenopathy
• Peripheral lymphadenopathy

Laboratory Findings

• There are no specific laboratory findings associated with primary effusion lymphoma.
• A lymph node biopsy is diagnostic of primary effusion lymphoma.
• Other laboratory findings consistent with the diagnosis of primary effusion lymphoma include complete blood count, blood chemistry studies, cytogenetic analysis, flow cytometry, immunohistochemistry, and immunophenotyping.

Imaging Findings

• There are no specific imaging study associated with primary effusion lymphoma.
• CT, MRI, and PET scan may be helpful in the diagnosis of primary effusion lymphoma.

Other Diagnostic Studies

• Primary effusion lymphoma may also be diagnosed using bone marrow aspiraton and biopsy.

Treatment

Medical Therapy

• The mainstay of therapy for primary effusion lymphoma is chemotherapy and antiretroviral therapy.
• Drug regimen: CHOP – Cyclophosphamide AND Doxorubicin AND Vincristine AND Prednisone

References

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