Angioimmunoblastic T-cell lymphoma (AITL, sometimes misspelled AILT, formerly known as "angioimmunoblastic lymphadenopathy with dysproteinemia"[2]: 747 ) is a mature T-cell lymphoma of blood or lymph vessel immunoblasts characterized by a polymorphous lymph node infiltrate showing a marked increase in follicular dendritic cells (FDCs) and high endothelial venules (HEVs) and systemic involvement.
The clinical findings typically include a pruritic skin rash and possibly edema, ascites, pleural effusions, and arthritis.
It is postulated that the originating cell for AITL is a mature (post-thymic) CD4+ T-cell that arises de novo,[1] or that the disease has a premalignant subtype.
[5][6] The Epstein–Barr virus (EBV) is observed in the majority of cases,[1] being identified in the reactive (i.e. non-malignant) B-cells that comprise part of the polymorphous infiltrate of AITL.
[1] The classical laboratory finding is polyclonal hypergammaglobulinemia, and other immunoglobulin derangements are also seen, including hemolytic anemia with cold agglutinins, circulating immune complexes, anti-smooth muscle antibodies, and positive rheumatoid factor.
[17] The typical patient with angioimmunoblastic T-cell lymphoma (AITL) is either middle-aged or elderly, and no gender preference for this disease has been observed.