How I Diagnose Angioimmunoblastic T-Cell Lymphoma

Area of Science:

• Hematology
• Oncology
• Pathology

Background:

• Angioimmunoblastic T-cell lymphoma (AITL) is a distinct subtype of peripheral T-cell lymphoma originating from T-follicular helper cells.
• The diagnosis of AITL presents challenges for pathologists due to its diverse clinical and histopathologic manifestations, often mimicking other conditions.

Purpose of the Study:

• To review the clinicopathologic features of AITL.
• To highlight diagnostic tools for practicing pathologists.
• To discuss common diagnostic challenges in AITL.

Main Methods:

• Literature review and synthesis of clinicopathologic features.
• Emphasis on diagnostic modalities for AITL.
• Discussion of differential diagnostic dilemmas.

Main Results:

• AITL displays varied histologic patterns with an often obscuring microenvironment.
• Atypical B-cell proliferations, including clonal expansion, are common and can mimic Hodgkin/Reed-Sternberg cells, leading to potential misdiagnosis.
• Recurrent genetic alterations identified through molecular studies can assist in differential diagnosis.

Conclusions:

• Accurate diagnosis of AITL requires an integrated approach.
• Combining clinical, morphologic, immunophenotypic, and molecular findings is essential for overcoming diagnostic complexities.
• This integrated strategy aids in distinguishing AITL from other reactive and neoplastic processes.