Morphologic Mimics of Metaplastic Carcinoma
There is considerable morphologic overlap among the spindle cell lesions of the breast, with metaplastic carcinoma being the principal entity to distinguish from its mimics. An algorithmic approach beginning with the clinical presentation and imaging features, along with an appreciation of subtle morphologic clues to the diagnosis of metaplastic carcinoma, in all its varieties, can enhance diagnostic acumen. Discussion will include the most appropriate immunohistochemical panels for each differential diagnostic consideration.
Originally published on September 2, 2025
Lecture Presenter
![]() | Laura C. Collins, MD Professor of Pathology |
Dr. Laura C. Collins is the vice chair of Anatomic Pathology and director of Breast Pathology at Beth Israel Deaconess Medical Center (BIDMC) in Boston, Massachusetts. She is a professor of Pathology at Harvard Medical School. Dr. Collins graduated from Charing Cross and Westminster Medical School in London and completed her anatomic and clinical pathology residency training at the Beth Israel Hospital in Boston, followed by a cytopathology fellowship at the same institution (now BIDMC). In 1998, Dr. Collins joined the faculty at BIDMC as a staff pathologist. During her tenure at BIDMC, she has served as the director of the residency training program in anatomic and clinical pathology as well as the director of the selective pathology fellowship training program. Nationally, Dr. Collins has served the United States and Canadian Academy of Pathology (USCAP) as a member of the Education Committee, chair of the Residency Advisory Subcommittee, and most recently, as a member of the USCAP Board of Directors. She has also served as the president of the Arthur Purdy Stout Society of Surgical Pathologists.
Dr. Collins is an internationally renowned breast pathologist. She has published numerous original articles, review articles, and book chapters on breast pathology. She has twice been the guest editor for a monograph on Current Concepts in Breast Pathology in the Surgical Pathology Clinics Series. She coauthored the popular pathology textbook entitled Biopsy Interpretation of the Breast, which is now in its third edition, and she was a contributor to several chapters in the WHO Classification of Tumours of the Breast, 4th edition, published in 2012, and Breast Tumours: WHO Classification of Tumours, 5th edition, published in 2019.
Her research interests are in breast cancer, and in particular, the understanding of precursor lesions and early breast neoplasia. In addition to her work in research, Dr. Collins is a committed educator, giving numerous lectures and postgraduate CME courses around the U.S. and the world to support the ongoing education of pathologists and pathologists-in-training in the diagnosis of breast disease.
Objectives
After this presentation, participants will be able to:
- Evaluate diagnostic criteria of common and uncommon spindle cell lesions of the breast in both core needle biopsy specimens and surgical excision specimens
- Discuss the uses and limitations of immunohistochemistry in resolving diagnostic problems in spindle cell lesions of the breast
- Recognize the histopathologic mimics of metaplastic carcinomas
Sponsored by:
University of Utah School of Medicine, Department of Pathology, and ARUP Laboratories


