Intravascular large B-cell 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: Intravascular lymphomatosis; Malignant angioendotheliomatosis

Overview

Intravascular large B-cell lymphoma is a very rare subtype of diffuse large B-cell lymphoma (DLBCL). It is also considered a distinct type of non-Hodgkin lymphoma (NHL) in the World Health Organization (WHO) classification system. Intravascular large B-cell lymphoma affects small blood vessels.

Classification

Based on the clinical presentation, intravascular large B-cell lymphoma may be classified into either Western variant or Asian variant.

Intravascular large B-cell lymphoma classification

Name	Description
Western variant	Western variant characterized by symptoms related to the main organ involved, predominantly neurological or cutaneous
Asian variant	Asian variant in which the patients present with multi-organ failure, hepatosplenomegaly, pancytopenia, and hemophagocytic syndrome. This is an aggressive lymphoma which responds poorly to chemotherapy. The poor prognosis reflects in part frequent delays in diagnosis because of a lack of detectable tumor masses.

Pathophysiology

Intravascular large B-cell lymphoma is a rare type of extranodal large B-cell lymphoma characterized by the selective growth of lymphoma cells within the lumina of vessels, particularly capillaries, with exception of larger arteries and veins.

Microscopic Pathology

• 

  At autopsy, many of the organs showed involvement by intravascular diffuse large B-cell lymphoma. The alveolar wall showed large atypical cells in the capillaries that were positive for CD20. Within the arteriole wall of the lung were these atypical cells as well.

• 

  At autopsy, many of the organs showed involvement by intravascular diffuse large B-cell lymphoma.The myocardium also showed these large atypical cells in the vessel lumen.

• 

  Retrospective evaluation of the bone marrow also showed inconspicuous large cells in clusters.

• 

  Retrospective evaluation of the bone marrow also showed inconspicuous large cells in clusters highlighted with CD20 (inset).

Causes

There are no established causes for intravascular large B-cell lymphoma.

Differentiating type page name here from other Diseases

Intravascular large B-cell lymphoma must be differentiated from other diseases such as:

• Hepatosplenic T-cell lymphoma
• B-cell chronic lymphocytic leukemia
• Mantle cell lymphoma
• Splenic marginal zone lymphoma

Epidemiology and Demographics

Age

The incidence of intravascular large B-cell lymphoma increases with age; the median age at diagnosis is 67 years.

Gender

Intravascular large B-cell lymphoma affects men and women equally.

Risk Factors

There are no established risk factors for intravascular large B-cell lymphoma.

Screening

According to the the U.S. Preventive Service Task Force (USPSTF), there is insufficient evidence to recommend routine screening for intravascular large B-cell lymphoma.

Natural History, Complications and Prognosis

• People with this type of lymphoma can also develop a very serious condition where certain parts of the immune system are activated (hemophagocytic syndrome).
• Hemophagocytic syndrome causes:

• Fever
• Enlarged liver and spleen (hepatosplenomegaly)
• A lower number of red blood cells, white blood cells and platelets in the blood (pancytopenia)

Diagnosis

Symptoms

Symptoms of the intravascular large B-cell lymphoma include:

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

Physical Examination

Vitals

• Fever is often present

Skin

• Skin rash

HEENT

• Cervical lymphadenopathy

Thorax

• Thoracic masses suggestive of central lymphadenopathy

Abdomen

• Abdominal masses suggestive of central lymphadenopathy
• Hepatosplenomegaly

Extremities

• Peripheral lymphadenopathy

Laboratory Findings

Laboratory tests for intravascular large B-cell lymphoma include:

• Complete blood count (CBC): pancytopenia
• Blood chemistry studies:
• Cytogenetic analysis
• Flow cytometry
• Immunohistochemistry
• Immunophenotyping

Biopsy

Lymph node biopsy is diagnostic of intravascular large B-cell lymphoma.

Other Imaging Findings

CT, MRI, and PET scan may be helpful in the diagnosis of intravascular large B-cell lymphoma.

• 

  Computed tomography (CT) scan of the chest showed diffuse interstitial thickening and ground glass opacities.

Treatment

Medical Therapy

Treatment of intravascular large B-cell lymphoma

Therapy	Description
Chemotherapy	Combination therapy : CHOP – Cyclophosphamide AND Doxorubicin AND Vincristine AND Prednisone
Radiation therapy	External beam radiation therapy may be used.

Related Chapters

• Richter's transformation
• T-cell lymphoma

Template:WikiDoc Sources