[Angioimmunoblastic T-cell lymphoma: histopathological grading and prognosis]

Area of Science:

• Hematopathology
• Oncology
• Molecular Pathology

Background:

• Angioimmunoblastic T-cell lymphoma (AITL) is an aggressive non-Hodgkin lymphoma with complex histological features.
• Accurate prognostic stratification is crucial for effective management of AITL patients.
• Identifying key histological and molecular markers can improve prognostication.

Purpose of the Study:

• To investigate the histological characteristics of AITL.
• To identify prognostic factors influencing patient survival in AITL.
• To correlate clinicopathological and molecular findings with clinical outcomes.

Main Methods:

• Retrospective analysis of pathological data from 62 AITL patients.
• Histological examination, immunohistochemistry (IHC), in situ hybridization (ISH), and single nucleotide polymorphism (SNP) gene mutation analysis were performed.
• Correlation of findings with clinical progression and overall survival.

Main Results:

• Significant expansion of follicular dendritic cell (FDC) areas (≥30%), increased plasma cells (≥10%), perivascular B cell distribution, increased p53 mutation-positive cells (≥40%), and high Ki-67 index (≥40%) were observed.
• RHOA and TET2 mutations were identified in 19 and 9 cases, respectively.
• Multivariate analysis identified CD38 positive cells <10%, Ki-67 ≥40%, RHOA, and TET2 mutations as independent risk factors for overall survival.

Conclusions:

• AITL can be stratified into distinct low-grade and high-grade prognostic groups.
• Prognostic grouping is based on FDC area expansion, plasma cell proliferation, B cell distribution, gene mutations, and clinical progression.
• Low-grade AITL exhibits slow progression, while high-grade AITL is highly invasive, impacting patient outcomes.