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Ira J. Bleiweiss, MD

Professor of Pathology and Laboratory Medicine
Director, Breast Pathology Subspecialty Service
University of Pennsylvania, Perelman School of Medicine
Philadelphia, Pennsylvania

Current Research

Goal: To evaluate mammography screening technologies on the frequency of pre-malignant diagnoses.

Impact: With the advancement of 3-D-digital breast tomosynthesis, assumptions are that it is better than the current 2-D mammography. Dr. Bleiweiss is challenging this assumption by comparing both technologies in detection and staging for breast lesions.  The results will provide evidence regarding which method is better to reduce unnecessary biopsies and ensure that threatening cancers are not missed. 

What’s next: He and his team will continue this investigation by reviewing patient biopsies with both technologies and comparing the frequency of each diagnosis as well as comparing subtypes and stages of malignancies.

Early pre-malignant changes in the breast can be a sign of increased risk of breast cancer that requires more frequent screening. 2-D digital mammography is the standard for breast cancer screening, but the more advanced 3-D tomosynthesis is assumed to be better. However, 3-D is not as widely available as 2-D technology. Dr. Bleiweiss is leading a study to compare the diagnoses from each technology to determine if one is better than the other, or whether the answer is dependent on type or stage of breast cancer.

Full Research Summary

Research area: Determining whether 2-D digital mammography or 3-D tomosynthesis is superior in detecting early pre-malignant changes in the breast.

Impact: Mammography has progressed rapidly from analog to digital, and thanks to these advances, the precision of diagnosis of benign, risk-associated lesions has increased. These include non-invasive lesions, such as atypical duct hyperplasia, radial scar, intraductal papilloma, atypical lobular hyperplasia, and in situ lobular carcinoma. Such early pre-malignant changes in patients can be a sign of increased risk of breast cancer, indicating that more frequent breast cancer screening is necessary.

2-D digital mammography has become the new standard for breast cancer screening, but the more advanced 3-D tomosynthesis is assumed to be better (though it is not as widely available as 2-D technology.) Dr. Bleiweiss aims to determine the appropriate use of 2-D mammography vs. tomosynthesis to detect early pre-malignant changes.
Current investigation: Dr. Bleiweiss has been exploring whether the range and frequency of benign diagnoses has changed with the advent of tomosynthesis and whether or not it leads to unnecessary biopsies.

What he’s accomplished so far: The team has completed pathology review of 200 cases of BRCA2-associated breast cancers to identify mutation specific changes. Thus far, they have not identified a BRCA2-specific profile, but will continue these efforts.

What’s next: The team will continue to compare the features of both benign and malignant histopathologic diagnoses and the stage of malignancies of cases that were diagnosed via tomosynthesis in comparison to those diagnosed via 2D-mammography.


Ira J. Bleiweiss, MD is a Professor of Pathology and Laboratory Medicine in the Perelman School of Medicine of the University of Pennsylvania.  He is director of the Breast Pathology Subspecialty Service at the Hospital of the University of Pennsylvania. Dr. Bleiweiss received his MD from St. Georges University School of Medicine, followed by residency in Anatomic and Clinical Pathology and fellowship in Surgical Pathology at The Mount Sinai Medical Center. After fellowship at Memorial Sloan Kettering Cancer Center, Dr. Bleiweiss returned to Mount Sinai, Department of Pathology to become Professor, Director of Surgical Pathology and Director of Anatomic Pathology. With more than 25 years of experience he oversees a completely subspecialized service dedicated to diagnosing breast lesions in specimens from hospital, as well as private practice outpatient settings.

Dr. Bleiweiss is well-known nationally and internationally for his expertise in breast pathology and is the author of more than 100 peer reviewed publications, largely related to breast cancer, many in the area of radiologic-pathologic correlation of image-guided breast core biopsies, a subject on which he co-authored a textbook.

His focus is distinctly multidisciplinary, and he is a past President of the International Society of Breast Pathology.

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BCRF Investigator Since


Area(s) of Focus