Angiosarcoma is a rare but very aggressive tumor. It occurs in all organs of the body, and approximately 8% of all angiosarcomas arise in the breast. We reported 2 cases of primary breast angiosarcomas in young women. The 2 patients showed similar clinical features, but were quite different in dynamic contrast-enhanced MR imaging. The 2 patients were treated with mastectomy and axillary sentinel lymph node dissection and confirmed by post-operative pathological test. We suggested that dynamic contrast-enhanced MR imaging was the most helpful imaging tool in the diagnosis and pre-operative evaluation of the breast angiosarcoma.© 2023 The Authors. Published by Elsevier Inc. on behalf of University of Washington.