Mammography and MRI manifestations of breast angiosarcoma

Breast angiosarcoma is rare and previous studies only focus on its pathology. This study aimed to summarize its imaging features.

Overall 17 patients pathologically confirmed with breast angiosarcoma were recruited. Eight patients underwent preoperative mammography, and 13 received preoperative MRI scan. The mammography and MRI findings were classified according to the ACR-BI-RADS-mammography/MR lexicon.

Mammography showed that 3 cases developed diffuse asymmetry occupying two or more quadrants of the affected breast and that 5 patients had lobulated or oval masses. The 13 patients' lesions presented as diffuse and slightly/significantly high homogeneous or heterogeneous signals on T1-weighted images, while the necrotic and cystic parts had relatively low signals. The hemorrhagic lesions in 7 cases had high signals on both T1- and T2-weighted images. A hemosiderin ring at the edge of an old hemorrhagic lesion had long and short signals on the T1- and T2-weighted images, respectively. Contrast-enhanced MRI revealed that the 13 patients' lesions had significant heterogeneous enhancement. Significant enhancement was observed in the early phase, and varying degrees of concentric enhancement was seen in the delayed phase.

The mammography findings are nonspecific. MRI scan is helpful in determining the malignancy of the lesions. Breast angiosarcoma usually shows heterogeneous signals on both T1-weighted and T2-weighted images. Due to their incomplete lumens and lack of thrombocytes, patients with angiosarcoma have a higher incidence of bleeding (nearly 50% in this study) than those with other malignant tumors. The pattern of the enhancement curve helps to distinguish this disease from the typical types of breast cancer.