Imaging features and management of high-risk lesions on contrast-enhanced dynamic breast MRI.

OBJECTIVE: Women at high risk for breast cancer and women with newly diagnosed breast cancer often undergo breast MRI. With the increasing availability of MRI-guided biopsy, high-risk lesions are not infrequently encountered. These high-risk lesions include atypical ductal hyperplasia, lobular carcinoma in situ, atypical lobular hyperplasia, papilloma, radial scar, and flat epithelial cell atypia. The management of these lesions is controversial and is often extended to high-risk lesions detected on mammography and ultrasound, with surgical excision usually recommended. The increasing use of MRI for suspicious lesions necessitates review of the imaging characteristics, frequency, and surgical outcome of high-risk lesions identified at MRI. This article addresses the frequency of high-risk lesions detected on breast MRI according to the current literature and discusses MRI features of high-risk lesions, including morphologic and enhancement kinetic characteristics. The surgical outcome for high-risk lesions identified at MRI-guided biopsy will be discussed. Finally, appropriate management guidelines for high-risk lesions identified on MRI-guided biopsy will be determined.
CONCLUSION: To our knowledge, no studies to date show definitive and specific characteristics for high-risk lesions. Underestimation of malignancy on MRI-guided biopsy currently warrants surgical management for all high-risk lesions. There is a need for prospective larger power studies.