Malignant phyllodes tumours of the breast: The case for revising WHO’s ‘full house’ diagnostic criteria Review


Authors: Tan, P. H.; Ellis, I. O.; Allison, K. H.; Badve, S. S.; Brogi, E.; Callagy, G.; Charafe-Jauffret, E.; Chen, C. J.; Chen, Y. Y.; Collins, L. C.; Cserni, G.; Djerroudi, L.; Foschini, M. P.; Fox, S. B.; Gobbi, H.; Gudi, M.; Harada, O.; Jaffer, S.; Kulka, J.; Kuroda, H.; Lakhani, S. R.; Li, X.; Moriya, T.; O'Toole, S.; Pinder, S. E.; Provenzano, E.; Quinn, C.; Raymond, W.; Sahin, A. A.; Schmitt, F.; Shaaban, A. M.; Shet, T.; Siziopikou, K. P.; Tang, P.; Tse, G. M.; Varga, Z.; Vincent-Salomon, A.; Wen, H.; Yamaguchi, R.; Yang, W.; Schnitt, S. J.; Rakha, E. A.
Review Title: Malignant phyllodes tumours of the breast: The case for revising WHO’s ‘full house’ diagnostic criteria
Abstract: Phyllodes tumours (PTs) of the breast present diagnostic challenges due to their complex histological features and potential for malignant behaviour. The World Health Organisation (WHO) classification requires the presence of five adverse histological criteria to categorise PTs as malignant, aiming to avoid overdiagnosis and improve diagnostic consistency. However, emerging evidence suggests that these strict criteria may underdiagnose tumours with metastatic potential and histological features that would otherwise be considered malignant in soft tissue tumours, leading to significant implications for prognosis and treatment. Recent studies have highlighted cases where tumours classified as borderline PT by WHO criteria exhibited metastatic behaviour, emphasising the need to refine the diagnostic framework. Microscopic criteria used to classify PT also vary among reporting pathologists, resulting in suboptimal reproducibility. This review examines the histological parameters utilised in the classification of malignant PT, highlights existing evidence gaps and analyses international breast pathologist survey data to propose a pragmatic diagnostic approach. We recommend redefining malignant PTs to include cases meeting four of the five WHO criteria, supplemented by comprehensive sampling and clinical context. This approach balances the risk of underdiagnosis with the need for standardised, reproducible diagnostic practices. Future collaborative efforts should focus upon developing evidence-based, biologically relevant classification systems and leveraging technological advancements to enhance diagnostic precision. These efforts aim to refine classification, improve prognostic accuracy and optimise patient management strategies. © 2025 The Author(s). Histopathology published by John Wiley & Sons Ltd.
Keywords: histopathology; review; reproducibility; biological marker; breast; phyllodes tumor; evidence based practice; histology; patient care; diagnosis; world health organization; metastasis potential; pathologist; soft tissue tumor; diagnostic test accuracy study; overdiagnosis; human; borderline state; neoplastic cell transformation; grade malignancy; phyllodes tumours; underdiagnosis
Journal Title: Histopathology
Volume: 87
Issue: 2
ISSN: 0309-0167
Publisher: Wiley Blackwell  
Publication status: Published
Date Published: 2025-08-01
Online Publication Date: 2025-04-13
Start Page: 169
End Page: 182
Language: English
DOI: 10.1111/his.15455
PROVIDER: scopus
PMCID: PMC12232237
PUBMED: 40223225
DOI/URL:
Notes: Review -- Source: Scopus
Altmetric
Citation Impact
BMJ Impact Analytics
MSK Authors
  1. Hannah Yong Wen
    305 Wen
  2. Edi Brogi
    519 Brogi