Benign Breast Lesions that Simulate Malignancy: Magnetic Resonance Imaging with Radiologic-Pathologic Correlation

The typical appearance of benign breast conditions on magnetic resonance imaging (MRI) is well established and diagnosis is usually easy. However, cases of benign breast lesions that are extremely difficult to differentiate from malignant breast tumors are occasionally encountered in MRI of the breast because overlap between benign and malignant lesions characteristics is found. This article describes the MRI features of a variety of suspicious breast conditions that were confirmed to be benign in the histopathologic study. We evaluated both enhancement kinetics and lesion morphological information to differentiate malignant from benign lesions. We also correlated the MRI findings with clinical data, and mammographic, ultrasound, and pathologic findings. Lesions evaluated included benign proliferative breast disease, fibroadenoma, intraductal papilloma, granular cell tumor, pseudoangiomatous stromal hyperplasia, fat necrosis, mastitis, inflammatory granuloma, epidermal inclusion cyst, and benign intramammary lymph node.