Angioimmunoblastic T-cell Lymphoma
Epidemiology and Etiology:
- Middle aged and elderly
- 1-2% of all NHLs
- EBV positive (>75%) (B cells mostly)
Common sites:
- Systemic usually
- Lymph nodes
- Spleen
- Skin
- Bone marrow
Gross features:
- Generalized peripheral lymphadenopathy
- Hepatosplenomegaly
- Skin rash
- Pleural effusion
- Ascites
Histologic features:
- Parial effacement of the lymph node architecture
- Regressed follicles (tiny follicles) often
- Bridging the lymph node capsule typically
- Hyperplastic germinal centers rarely
- polymorphous infiltrate in the paracortex:
- polymorphous population of small to medium
atypical lymphocytes
- clear to pale cytoplasm
- distinct cell membranes
- minimal cytologic atypia
- small, reactive lymphoctyes
- eosinophils
- plasma cells
- histiocytes
- follicular dendritic cells increased
- large basophilic blasts (B-cell phenotype)
maybe
- Reed-Sternberg-like cells maybe
- prominent proliferation of high endothelial
venules
Immunophenotype & Special Stains:
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Marker:
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Sensitivity:
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Specificity:
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Mature T
cells, admixture of CD4 > CD8, variable loss of some pan-T antigens
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Polyclonal
plasma cells
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CD21
(follicular dendritic cells conspicuous, surrounding HEV’s)
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TdT (neg)
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EBER (isolated
neoplastic or reactive cells only)
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often
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Molecular features:
- TCR gene rearrangement (75-90%)
- Immunoglobulin gene rearrangement (25-30%)
- Correlates with expanded EBV+ B-cell clones
- EBV sequences (mainly in B cells)
- Trisomy 3
- Trisomy 5
- +X
- Gains by CGH:
- Losses by CGH:
Other features:
- Advanced stage on presentation usually
- Aggressive clinical course
- Median survival <3y
- Patients often succumb to infections
- 2ndary EVB+ B-cell lymphomas have been reported
- Immunodeficiency
- Arthritis
- Serum markers:
- Polyclonal hypergammaglobulinemia
- Circulating immune complexes, cold agglutanins
with hemolytic anemia
- Rheumatoid factor positive
- Anti-smooth muscle antibodies positive
References:
- WHO blue book (2001) (2008)