Radiologic and Pathologic Correlation for Angiolipomas of the Breast

Angiolipomas of the breast are rare; however, they are an important entity for the radiologist who determines radiologic-pathologic concordance and recommends appropriate management. They can present as a palpable concern, prompting diagnostic workup, or can be detected on screening breast examinations. They often present as a circumscribed low-density mass on mammography, which is hyperechoic on sonography; associated fibrin thrombi can produce soft tissue density and/or hypoechoic foci that appear hypointense on T1-weighted MRI. Due to the nonspecific radiographic appearance, tissue sampling is often required for definitive diagnosis. Pathologically, angiolipomas can be difficult to distinguish from angiosarcomas; however, scattered microthrombi in small blood vessels are a typical feature of angiolipomas. Generally, in the setting of radiologic-pathologic concordance, angiolipomas do not need to be excised and can be followed clinically when palpable. Surgical excision can be pursued when certain high-risk features, such as nuclear enlargement, an infiltrative pattern, endothelial mitoses, and a high proliferation rate, are present in the core-needle biopsy specimen.