Decision making for breast lesions initially detected at contrast-enhanced breast MRI

• Published in: American journal of roentgenology (1976) Vol. 201; no. 6; pp. 1376 - 1385
• Main Authors: Yamaguchi, Ken, Schacht, David, Sennett, Charlene A, Newstead, Gillian M, Imaizumi, Takeshi, Irie, Hiroyuki, Abe, Hiroyuki
• Format: Journal Article
• Language: English
• Published: United States 01-12-2013
• Subjects: Adult; Aged; Biopsy; Breast Neoplasms - diagnosis; Breast Neoplasms - diagnostic imaging; Contrast Media; Decision Making; Female; Gadolinium DTPA; Humans; Lymphatic Metastasis; Magnetic Resonance Imaging - methods; Middle Aged; Retrospective Studies; Ultrasonography, Mammary
• ISSN: 0361-803X; 1546-3141
• DOI: 10.2214/ajr.12.8953

The purpose of this study was to assess the clinical significance of breast lesions initially detected at contrast-enhanced breast MRI and to consider how to manage those lesions in accordance with the imaging findings and the indication for MRI.
A retrospective study of 4260 consecutive breast MRI examinations was performed to identify MRI-detected enhancing lesions. In 4260 studies, 554 MRI-detected lesions were found in 417 patients, and 134 (24%) of the lesions were malignant. Pathologic confirmation was obtained for 319 (58%) lesions. Results of the subsequent imaging workup, biopsy, surgery, and imaging follow-up were reviewed.
The median size of the lesions was 89 mm (malignant, 15.45 mm; benign, 7.48 mm). Irregular shape, irregular or spiculated margins, and heterogeneous or rim enhancement were seen significantly more often in malignant mass lesions (p < 0.001). Malignant lesions were more likely to exhibit rapid enhancement (p < 0.001). Benign lesions were more likely to have persistent kinetics (p < 0.001). There was a statistically significant difference (p < 0.001) between malignant (58/87, 67%) and benign lesions (128/287, 45%) with respect to sonographic detection at second-look ultrasound examinations. Malignant lesions were most often detected in patients with metastatic axillary lymph nodes with an unknown primary tumor (8/8, 100%), followed by patients with positive or close margins in recent breast cancer surgery (45/76, 59%), and patients with newly diagnosed breast cancer (44/115, 38%).
Management of MRI-detected lesions should be based on both MRI findings and the patient's indication for MRI.