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Clinical manifestations, pathologic features, and diagnosis of angioimmunoblastic T-cell lymphoma
Arnold S Freedman, MD
Jon C Aster, MD
Section Editor
Andrew Lister, MD, FRCP, FRCPath, FRCR
Deputy Editor
Rebecca F Connor, MD
Last literature review version 18.2: mayo 2010 | This topic lastupdated: noviembre 18, 2009 (More)
INTRODUCTION — The peripheral T-cell lymphomas (PTCL) are a heterogeneous group of generally aggressive neoplasms that constitute less than 15 percent of all non-Hodgkin lymphomas (NHLs) in adults [1-5]. (See "Classification of the hematopoietic neoplasms".)

Among these, in decreasing frequency of occurrence, are:

• Peripheral T-cell lymphoma, not otherwisespecified
• Anaplastic large cell lymphoma, primary systemic type
• Angioimmunoblastic T-cell lymphoma
• Extranodal NK/T-cell lymphoma, nasal type
• Subcutaneous panniculitis-like T-cell lymphoma
• Enteropathy associated T-cell lymphoma
• Hepatosplenic T-cell lymphoma

Angioimmunoblastic T-cell lymphoma (AITL) is one of the more common PTCLs and is thought to arisefrom peripheral CD4 positive T-cells, perhaps corresponding to a subset of follicular helper T-cells [6-8]. Patients typically present with the acute onset of a systemic illness and lymph node biopsy demonstrates a polymorphous infiltrate with a prominent proliferation of high endothelial venules and follicular dendritic cells.

The clinical presentation, pathologic features, and diagnosis ofAITL will be discussed here. The other NK/T cell lymphomas and the pathobiology and treatment of the PTCLs are presented separately. (See appropriate topic reviews).

EPIDEMIOLOGY — AITL is one of the more common peripheral T-cell lymphomas (PTCLs) encountered in Western countries. Incidence varies by geography with the highest rates in Europe (28 percent of PTCLs) and lower rates in NorthAmerica (15 percent PTCLs) and Asia (17 percent PTCLs) [9,10]. In the United States the incidence is approximately 0.05 cases per 100,000 person years [11].

AITL usually affects older adults with a median age of approximately 60 years [12-14]. Incidence appears to be approximately equal in men and women, although some reports have noted a slightly male predominance [12-14].

CLINICALFEATURES — Patients with AITL typically present with the acute onset of a systemic illness. Less commonly, patients may present with asymptomatic lymphadenopathy.

Symptoms frequently include [13,15-18]:

• Generalized lymphadenopathy (95 percent)
• Hepatomegaly (50 to 70 percent)
• Splenomegaly (70 percent)
• Systemic B symptoms of fevers, night sweats, or weight loss (70 to 85 percent)• Rash (50 to 60 percent)
• Polyarthritis (20 percent)
• Ascites/effusions (20 to 35 percent)

The rash is usually pruritic and may demonstrate lymphohistiocytic vasculitis on biopsy. The vast majority of patients present with advanced (stage III/IV) disease. The bone marrow is involved in 50 to 60 percent of cases. While extranodal involvement is common, it is uncommon for AITL topresent at a single, isolated extranodal site.

Laboratory abnormalities are common and include [13,15-18]:

• Elevated serum lactate dehydrogenase (LDH) and the erythrocyte sedimentation rate (ESR) in approximately 70 and 45 percent of cases, respectively.
• Polyclonal hypergammaglobulinemia is seen in 50 to 80 percent, but some cases demonstrate hypogammaglobulinemia or a monoclonalgammopathy.
• Positive Coombs test, with or without hemolysis (up to 30 percent).
• Elevated beta-2 microglobulin (approximately 65 percent).
• Lymphopenia, anemia, and thrombocytopenia are seen in approximately 45, 50, and 20 percent, respectively. Hypereosinophilia is noted in 30 to 40 percent.
• Approximately half of patients demonstrate hypoalbuminemia.

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