Metastatic Choriocarcinoma to the Breast: Mammography and Color Doppler Ultrasound

This chapter presents the role of mammography and color Doppler ultrasound in the diagnosis of metastatic choriocarcinoma to the breast. The most common mammographic appearance of metastases is of one or more well-circumscribed masses located in the upper and outer quadrant of the breast. Typically, there is no spiculation, architectural distortion, skin thickening, or other signs of surrounding desmoplastic reaction, which characterize the majority of primary breast carcinomas. However, the mammographic findings of breast metastases can be variable and range from normal to a pattern of diffuse skin thickening that simulates inflammatory carcinoma. The mammographic appearances of metastatic hematologic malignancies can vary from discrete to ill-defined masses that may be obscured by benign proliferative breast changes. Benign lesions such as cysts or fibroadenomas can have an appearance similar to breast metastases on mammography. Magnification and spot compression images may be useful as the margins of a metastasis are slightly more irregular than those of a fibroadenoma or cyst. Medullary, mucinous, and papillary carcinomas of the breast should also be included in the differential diagnosis of breast metastases on mammography. Ultrasonography reliably distinguishes cystic from solid breast lesions. A variety of sonography findings are reported in patients with breast metastases. Characteristic lesions are rounded or oval with a low echogenicity and a well-defined posterior wall. They have macrolobulations and are aligned with their long axis parallel to the skin. Multiple lesions in the breast maintain the same sonographic characteristics. Since there is considerable overlap in the gray-scale sonographic appearance of breast metastasis and benign breast lesions such as fibroadenomas, color Doppler sonography can be used to assess the vascularity of the lesion for better characterization.