Metastatic tumors in the breast: sonographic findings.

The sonographic findings observed in eight patients with metastatic tumors in the breast were reviewed. Solitary breast nodules were present in four patients; multiple metastases were seen in the other four patients, with bilateral lesions in two of them. A total number of 20 breast masses was appreciated. All lesions had a round or oval shape and hypoechoic, solid echopattern, when compared with the surrounding breast parenchyma. In three patients, they presented with many small medium-level internal echoes while, in the other five patients they were almost anechoic, with only a few low-level echoes within. Regular and well-defined margins were seen in four patients; in the remaining four patients, irregular walls were seen. The posterior walls of the lesions were well defined, and great acoustic attenuation was never seen. In one case, slight acoustic enhancement was present posterior to the lesions from non-Hodgkin's lymphoma. Multiple masses in the same patient always had the same sonographic features. While evaluating a breast mass in a patient with a known malignancy elsewhere in the body, the absence of an acoustic shadow posterior to the lesion may allow the metastatic nature of the disease to be considered as a diagnostic possibility.