Angioimmunoblastic T-Cell lymphoma: a critical analysis of clinical, morphologic and immunophenotypic features

Angioimmunoblastic T-cell lymphoma (AITL), a subtype of peripheral T-cell lymphoma (PTCL), is characterized by unique clinical and biological features. Its diagnosis remains a challenge as clinical presentation as well as pathologic findings are frequently misleading.

We retrospectively analyzed the clinical, morphological and immunophenotypic spectrum of 17 cases of histologically proven AITL.

The mean age was 54 years and male to female ratio was 2.4. Common clinical features included generalized lymphadenopathy (60%), hepatomegaly (70%), splenomegaly (50%), anemia (80%) and polyclonal hypergammaglobulinemia (100%). Microscopically, three architectural patterns; pattern I (6%), pattern II (41%) and pattern III (53%) were observed. Bone marrow infiltration was seen in 60% cases and 30% cases revealed plasmacytosis. Absence of follicles, polymorphous infiltrate, extra-follicular follicular dendritic cell (FDC) proliferation, high endothelial venules (HEV) prominence and neoplastic T-cells were the diagnostic features of AITL. CD10 positivity (47%), clear cells in the background (59%) admixture with large size CD20+ B-immunoblasts (35%) and bone marrow plasmacytosis (50%) were common observations.

Awareness of various morphological and immunophenotypic complexities of AITL and distinction from reactive adenopathies and other types of lymphomas that mimic AITL is underscored in this study.