Matteo Brunelli, MD
Anatomic Pathology, Department of Pathology, University of Verona, Verona, Italy

Erminia Manfrin, MD
Anatomic Pathology, Department of Pathology, University of Verona, Verona, Italy

Guido Martignoni, MD
Anatomic Pathology, Department of Pathology, University of Verona, Verona, Italy

Keith Miller, MD
UK National External Quality Assessment Scheme, University College London, London, England

Andrea Remo, MD
Anatomic Pathology, Department of Pathology, University of Verona, Verona, Italy

Daniela Reghellin, MD
Anatomic Pathology, Department of Pathology, University of Verona, Verona, Italy

Samantha Bersani, BaD
Anatomic Pathology, Department of Pathology, University of Verona, Verona, Italy

Stefano Gobbo, MD
Anatomic Pathology, Department of Pathology, University of Verona, Verona, Italy

Albino Eccher, MD
Anatomic Pathology, Department of Pathology, University of Verona, Verona, Italy

Marco Chilosi, MD
Anatomic Pathology, Department of Pathology, University of Verona, Verona, Italy

Franco Bonetti, MD
Anatomic Pathology, Department of Pathology, University of Verona, Verona, Italy

Keywords: Breast carcinoma; HER2/neu; Intratumoral heterogeneity; Fluorescence in situ hybridization; FISH; American Society of Clinical Oncology/College of American Pathologists guidelines

Upon completion of this activity, you will be able to:

• define the American Society of Clinical Oncology/College of American Pathologists criteria for HER2/neu amplification.
• discuss the likelihood of tumoral heterogeneity in HER2/neu amplified cases.
• discuss the contribution of polysomy of chromosome 17 to 3+ immunohistochemical staining for HER2/neu.
• define the role of HER2/neu testing in selecting patients for possible trastuzumab therapy.