AITL : Introduction

Comments:
Introduction: Angioimmunoblastic T-cell lymphoma (AITL) is the second most common specific subtype of peripheral T-cell lymphoma and it makes up 1% to 2% of all non-Hodgkin lymphomas. It is a systemic disease that presents with generalized lymphadenopathy, hepatosplenomegaly, constitutional symptoms, skin rash, anemia, and polyclonal hypergammaglobulinemia.

It arises from the follicular helper T cells of the germinal center and is now placed under the category of nodal T-cell lymphomas with T follicular helper phenotype. The follicular helper T-cells interact with B cells and promote their survival, immunoglobulin class-switch recombination, and somatic hypermutation. The play an important role in the formation of high-affinity plasma cells and memory B cells.

Terminology: AITL has been known in the past as angioimmunoblastic lymphadenopathy with dysproteinemia (AILD), immunoblastic lymphadenopathy, lymphogranulomatosis X, and AILD-type T-cell lymphoma.

In this low power image of AITL, the nodal architecture is largely effaced and replaced by ill-defined nodular/follicular areas.