E1102. When 5 is Benign: A Pictorial Review of Breast Malignancy Mimics
There are a multitude of benign, high-risk, inflammatory, post-surgical, and artifactual breast entities that can mimic features of malignancy. Frequently, these findings prompt tissue biopsy and not infrequently, they cause additional workup due to radiologic-pathologic discordance, resulting in both emotional stress and financial burden for patients. Based on our institution’s own experience, the most common false discordant entities triggering additional excisional biopsy are stromal fibrosis, fat necrosis, and radial scar on final pathology.
Educational Goals / Teaching Points
The objectives of this exhibit are to 1) recognize common and uncommon mimics of breast malignancy and 2) appreciate their mammographic, ultrasound, and MRI imaging characteristics with the goals of reducing radiologic-pathologic discordance and unnecessary surgical interventions.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Benign entities include fat necrosis, stromal fibrosis, sclerosing adenosis, fibroadenoma, hemangioma, pseudoangiomatous stromal hyperplasia, and intramammary lymph node. High-risk entities include atypical lobular hyperplasia, atypical ductal hyperplasia, lobular carcinoma in situ, papilloma, radial scar/complex sclerosing lesion, and phyllodes tumor. Inflammatory entities include mastitis, diabetic mastopathy, and Mondor disease. Post-surgical entities include post-surgical changes, scar tissue, FloSeal, and Bovie artifact. Other artifacts include dead pixels, dust on detector, and motion artifact.
Multiple benign breast pathologies can mimic breast malignancies on imaging. Awareness of these entities and their imaging characteristics can help guide radiologic-pathologic discordance and avoid unnecessary interventions.