ABSTRACT
BACKGROUND: Extramammary findings (EMFs) are common on breast magnetic resonance imaging (MRI). METHODS: A retrospective review of breast MRIs in breast cancer patients between January 2009 and December 2014 was performed to identify EMF occurrences, resultant evaluation, and added cost. RESULTS: EMFs were noted in 185 (59%) of 316 MRIs. Overall, 201 new EMFs were identified with 178 (89%) benign and 23 (11%) malignant. New malignant findings included 19 metastatic nodes (18 axillary, 1 internal mammary) and 4 primary malignancies (2 thyroid, 2 lung). New malignant nonaxillary EMFs occurred at a rate of 1.6% (5/316). EMFs resulted in 65 patients undergoing 98 imaging studies, 37 procedures, and 10 consultations with a median (range) total charge of $3,491 ($222 to $29,076] and out of pocket cost of $2,206 ($44 to $12,780) per patient. CONCLUSIONS: EMFs occurred in more than half of our patients, were usually benign, and frequently led to additional testing and costs.