Department of Histopathology, University of Nottingham and the Nottingham University Hospitals NHS Trust, Nottingham City Hospital, Nottingham, UK.
Histopathology. 2021 Oct;79(4):607-618. doi: 10.1111/his.14397. Epub 2021 Jun 21.
Phyllodes tumours (PT) are rare and distinct breast tumours, which span a morphological continuum. Classification into benign, borderline and malignant categories reflects their biology and clinical behaviour and is essential to guide management. This study aims to assess the diagnostic agreement of PT using the UK National Health Service Breast Screening Programme (NHSBSP) breast pathology external quality assurance (EQA) scheme data.
Twenty-six PTs were identified in the EQA scheme, which were diagnosed by an average of 607 participants/circulation. Data on diagnostic categories were collected and representative slides were reviewed. The level of concordance between reporting pathologists was assessed. There were 14 benign, six borderline and six malignant PT. The overall rate of diagnosis agreement was 86% when analysed as benign lesions, borderline PT and malignant lesions, which decreased to 79% when diagnosed as PT (irrespective of grade) and to 63% when the diagnosis was further refined to PT categories (benign, borderline and malignant PTs). The highest agreement rate was observed in malignant PT (86%) and the lowest in borderline PT (42%). Malignant heterologous elements, stromal overgrowth and leaf-like architecture are features associated with higher concordance rates. Lower-priority features were stromal expansion, clefting and multinodularity.
The concordance of PT diagnosis, as an entity, is high, but its classification into benign, borderline and malignant has variable agreement levels, with borderline tumours having the lowest concordance rate. More research to refine the diagnostic criteria for categorisation of PT is warranted to improve concordance between pathologists.
叶状肿瘤（PT）是一种罕见且独特的乳腺肿瘤，具有形态学连续性。将其分为良性、交界性和恶性类别反映了其生物学和临床行为，对于指导管理至关重要。本研究旨在使用英国国民保健服务乳房筛查计划（NHSBSP）乳房病理学外部质量保证（EQA）计划数据评估 PT 的诊断一致性。
在 EQA 计划中鉴定了 26 个 PT，由平均 607 名参与者/循环诊断。收集了诊断类别的数据，并对代表性幻灯片进行了审查。评估了报告病理学家之间的一致性水平。有 14 个良性、6 个交界性和 6 个恶性 PT。当分析为良性病变、交界性 PT 和恶性病变时，报告病理学家之间的总体诊断一致性率为 86%，当诊断为 PT（不分等级）时，一致性率降至 79%，当诊断进一步细化为 PT 类别（良性、交界性和恶性 PT）时，一致性率降至 63%。恶性异源成分、基质过度生长和叶状结构是与更高一致性率相关的特征。交界性 PT 的一致性率最低（42%），而恶性 PT 的一致性率最高（86%）。较低优先级的特征是基质扩张、裂隙和多结节性。
作为一个实体，PT 的诊断一致性很高，但将其分类为良性、交界性和恶性的一致性水平存在差异，交界性肿瘤的一致性率最低。需要进一步研究以细化 PT 分类的诊断标准，以提高病理学家之间的一致性。
