Primary Malignant Lymphoma of the Breast: Mammographic and Ultrasonographic Findings.

Malignant lymphoma rarely involves the breast. We discribe four cases of primary breast lymphoma encountered in our institution from 1979 through 1996, focusing on mammographic and ultrasonographic findings. The lymphomas were demonstrated by mammography as a well-defined mass in one case, an ill-defined mass in two cases and as diffuse increased opacity in one case. No desmoplastic change or calcification was noted. In 3 cases ultrasonography was used, revealing hypoechoic masses with (1 case) or without (2 case) posterior enhancement. During the past two years, 45 of 197 cancers (23%) were demonstrated as a mass without desmoplastic change or calcification by mammography and ultrasonography at our institution. It can be difficult to distinguish malignant lymphoma from more common diseases of the breast, such as carcinoma, by mammography and ultrasonography.