Lymphoma and plasma cell neoplasms
T / NK cell disorders
Angioimmunoblastic T cell lymphoma

Author: Dragos Luca, M.D. (see Authors page)

Revised: 24 March 2017, last major update September 2011

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PubMed search: angioimmunoblastic T cell [title] lymphoma

Cite this page: Angioimmunoblastic T cell lymphoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/lymphomanonBAITL.html. Accessed April 30th, 2017.
Definition / general
  • Peripheral T cell lymphoma characterized by systemic disease, a polymorphous infiltrate involving lymph nodes, with a prominent proliferation of high endothelial venules and follicular dendritic cells (WHO 2008)
Terminology
  • Formerly called angioimmunoblastic lymphadenopathy (with or without dysproteinemia, AILD), an atypical reactive process prone to lymphomatous transformation; currently considered a lymphoma from the outset
  • Other names used in the past: AILD-type T cell lymphoma, lymphogranulomatosis X, diffuse mixed small and large cell immunoblastic lymphoma
Epidemiology
  • 15% - 20% of peripheral T cell lymphomas
  • 1% - 2% of non-Hodgkin lymphomas
  • Middle aged and elderly patients
  • M:F ratio 1:1
  • More common in Caucasians than in Africans or Asians
Sites
  • Lymph nodes are primary site
  • Virtually all patients have generalized lymphadenopathy
  • Frequent involvement of spleen (50% - 70%), liver (50% - 70%), skin (50%), pleuropulmonary (40%) and bone marrow (60% - 90%, Am J Clin Pathol 2006;126:29)
Etiology
  • EBV associated (B cells are EBV+), but the neoplastic T cells are EBV negative
  • May occur after penicillin / drug administration (27% of cases in one study)
Clinical features
  • Usually presents with advanced stage disease
  • Hepatosplenomegaly, polyclonal hypergammaglobulinemia, fever, weight loss, skin rash, often with pruritus, pleural effusion, arthritis, ascites
Laboratory
  • Circulating immune complexes, cold agglutinins with hemolytic anemia, positive rheumatoid factor, anti smooth muscle antibodies
  • Expansion of EBV+ B cells is probably due to immunodeficiency
Case reports
Treatment
  • Moderately aggressive; may respond to steroids, may progress to diffuse large B cell lymphoma (most common), classical Hodgkin lymphoma, plasmacytoma, small B cell lymphoma, peripheral T cell lymphoma
  • Median survival < 3 years; death usually due to infectious complications
Postulated normal counterpart
  • CD4+ follicular helper T cell
Microscopic (histologic) description
  • Partial effacement of lymphonodular architecture, often with perinodal infiltration but with preservation of subcapsular and trabecular sinuses
  • Prominent arborizing high endothelial venules with thickened, hyalinized PAS+ walls surrounded by CD21+ follicular dendritic cells and irregular homogenous eosinophilic material
  • Burnt out germinal centers with increased follicular dendritic cell meshworks (mediated through expression of CXCL13 by neoplastic follicular helper T cells)
  • Predominantly paracortical aggregates of polymorphic small to medium sized cells with clear / pale cytoplasm, distinct cell membranes and minimal cytologic atypia
  • Small clusters of neoplastic cells around follicles and high endothelial venules, variable numbers of small reactive lymphocytes, eosinophils, plasma cells, histiocytes
  • Paracortical expansion of B immunoblasts linked to the functional properties of neoplastic follicular helper T cells
  • Three different histologic patterns described, I - III, with increasing degrees of architectural effacement, commonly coexisting in the same specimen, arbitrary cutoffs

Bone marrow:
  • Focal or diffuse marrow involvement
  • Focal lesions have indistinct margins
  • Contain polymorphous infiltrate of lymphocytes, immunoblasts, plasma cells, histiocytes, eosinophils and neutrophils
  • Often vascular proliferation with prominent endothelial cells and fibroblasts
  • Perivascular clustering of neoplastic clear cells in 41%
  • Variable epithelioid histiocytes
  • Usually no amorphous PAS+ material (found in nodal lesions)
  • Uninvolved marrow may be hypercellular

Peripheral blood:
  • Reactive lymphocytes, immunoblasts, immunocytes, increased eosinophils, various cytopenias, rouleaux
  • May also see circulating lymphoma cells
Microscopic (histologic) images

Images hosted on PathOut server:

Various images



Images hosted on other servers:

Various images

Cytology description
  • Small to large cells with moderate to faint basophilic cytoplasm without azurophilic granules and sometimes with microvacuoles, often irregular or indented nuclei, moderately condensed chromatin
Cytology images

Images hosted on other servers:

Peripheral blood: atypical lymphocytes

Positive stains
Negative stains
  • CD8, CD56, pan B cell markers, immunoglobulins, cytotoxic antigens, CD1a, CD99, TdT
Electron microscopy description
  • Lymphocytes with cytoplasmic vacuoles thought to correspond to neoplastic cells
  • High endothelial venules: swollen endothelial cells with walls thickened by basement membrane-like material and immunoglobulin deposition
  • Intercellular collagen and immunoglobulins correspond to the eosinophilic PAS+ material
Molecular / cytogenetics description
  • Clonal rearrangement of T cell receptor genes (75% - 90%) or IgH (25% - 30%)
  • Most frequent cytogenetic abnormalities: +3, +5, +X
  • Other: +22q, +19, +11q13, -13q
Differential diagnosis