Breast lesions of uncertain malignant nature and limited metastatic potential: proposals to improve their recognition and clinical management.
Breast lesions comprise a family of heterogeneous entities with variable patterns of presentation, morphology and clinical behaviour. The majority of breast lesions are classified traditionally into benign and malignant conditions and their behaviour can, in the vast majority of cases, be predicted with a reasonable degree of accuracy. However, there remain lesions which show borderline features and lie in a grey zone between benign and malignant, as their behaviour cannot be predicted reliably. Defined pathological categorization of such lesions is challenging, and for some entities is recognized to be subjective and include a range of diagnoses, and forms of terminology, which may trigger over- or undertreatment. The rarity of these lesions makes the acquisition of clinical evidence problematic and limits the development of a sufficient evidence base to support informed decision-making by clinicians and patients. Emerging molecular evidence is providing a greater understanding of the biology of these lesions, but this may or may not be reflected in their clinical behaviour. Herein we discuss some breast lesions that are associated with uncertainty regarding classification and behaviour, and hence management. These include biologically invasive malignant lesions associated with uncertain metastatic potential, such as low-grade adenosquamous carcinoma, low-grade fibromatosis-like spindle cell carcinoma and encapsulated papillary carcinoma. Other lesions of uncertain malignant nature remain, such as mammary cylindroma, atypical microglandular adenosis, mammary pleomorphic adenoma and infiltrating epitheliosis. The concept of categories of (1) breast lesions of uncertain malignant nature and (2) breast lesions of limited metastatic potential are proposed with details of which histological entities could be included in each category, and their management implications are discussed.
Department of Histopathology, Nottingham City Hospital NHS Trust, Nottingham University, Nottingham, UK.
Emad A
EA
Rakha
Departments of Pathology and Internal Medicine, Clarian Pathology Laboratory of Indiana University, Indianapolis, IN, USA.
Sunil
S
Badve
Sezione Anatomia Istologia e Citologia Patologica 'M. Malpighi', Università-ASL Ospedale Bellaria, Bologna, Italy.
Vincenzo
V
Eusebi
Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
Jorge S
JS
Reis-Filho
Pathology Department, Peter MacCallum Cancer Centre, St Andrews Place, East Melbourne, Victoria, Australia.
Stephen B
SB
Fox
University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
David J
DJ
Dabbs
German Breast-Screening Program, Reference Centres Berlin and Muenster, Department of Pathology, Dietrich Bonhoeffer Medical Centre, Neubrandenburg, Germany.
Thomas
T
Decker
Department of Histopathology, Nottingham City Hospital NHS Trust, Nottingham University, Nottingham, UK.
Zsolt
Z
Hodi
Department of Pathology, Nagoya Medical Center, Nagoya, Japan.
Shu
S
Ichihara
Department of Histopathology, Nottingham City Hospital NHS Trust, Nottingham University, Nottingham, UK.
Andrew H S
AH
Lee
Department of Pathology, Hospital Universitario Ramón y Cajal, Instituto de Investigación Sanitaria Ramón y Cajal (IRYCIS), Madrid, Spain.
José
J
Palacios
Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA.
Andrea L
AL
Richardson
Department of Pathology, Institute Curie, Paris, France.
Anne
A
Vincent-Salomon
Department of Medicine and Pathology, Laboratoire National De Santé, Luxembourg, Luxembourg.
Fernando C
FC
Schmitt
Department of Pathology, Singapore General Hospital, Singapore, Singapore.
Puay-Hoon
PH
Tan
Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong.
Gary M
GM
Tse
Department of Histopathology, Nottingham City Hospital NHS Trust, Nottingham University, Nottingham, UK.
Ian O
IO
Ellis
D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000473:pathology*; D002277:Carcinoma / Q000473:pathology*; D018196:Carcinoma, Adenosquamous / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D005350:Fibroma / Q000473:pathology*; D006801:Humans
behaviour; breast lesions; differentiation; lesions of uncertain malignant potential; lesions of uncertain metastatic potential; terminology