Bosch-Schips Jan, Parisi Xenia, Climent Fina, Vega Francisco
Department of Pathology, Hospital Universitari de Bellvitge, University of Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain.
Hematopathology, Division of Pathology and Laboratory Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.
Hum Pathol. 2025 Feb;156:105676. doi: 10.1016/j.humpath.2024.105676. Epub 2024 Oct 25.
Follicular lymphoma (FL) is a neoplasm that originates from germinal center B cells and typically forms at least a partial follicular pattern. Approximately 85% of FL cases harbor the t(14;18)(q32;q21)/IGH::BCL2 which leads to the overexpression of BCL2. These cases are referred to as classic FL in the current World Health Organization classification [1]. These neoplasms often exhibit hallmark epigenetic deregulation due to recurrent mutations in genes such as KMT2D, CREBBP, and EZH2, with KMT2D and CREBBP considered founding events in FL lymphomagenesis. In contrast, about 15% of FL cases are negative for the t(14;18), which could present diagnostic challenges. These cases may lack the typical genetic markers and require careful pathological and molecular analysis for accurate diagnosis. This review aims to provide an up-to-date pathology resource on FL, focusing on the pathological and molecular characteristics of these neoplasms. We will detail the diagnostic criteria for FL and emphasize the importance of genetic and mutational analyses in accurately characterizing and distinguishing FL subtypes. Furthermore, we will propose methodologies and best practices for the diagnostic work-up of FL to enhance diagnostic accuracy.
滤泡性淋巴瘤（FL）是一种起源于生发中心B细胞的肿瘤，通常至少形成部分滤泡模式。大约85%的FL病例存在t(14;18)(q32;q21)/IGH::BCL2，这导致BCL2过度表达。在当前世界卫生组织分类中，这些病例被称为经典FL [1]。由于KMT2D、CREBBP和EZH2等基因的反复突变，这些肿瘤常常表现出典型的表观遗传失调，其中KMT2D和CREBBP被认为是FL淋巴瘤发生的起始事件。相比之下，约15%的FL病例t(14;18)呈阴性，这可能带来诊断挑战。这些病例可能缺乏典型的遗传标志物，需要仔细的病理和分子分析以进行准确诊断。本综述旨在提供关于FL的最新病理学资源，重点关注这些肿瘤的病理和分子特征。我们将详细阐述FL的诊断标准，并强调基因和突变分析在准确表征和区分FL亚型中的重要性。此外，我们将提出FL诊断检查的方法和最佳实践，以提高诊断准确性。
