Primary malignant lymphoma of the breast.

Primary malignant lymphoma of the breast is a rare tumor. Recently, we encountered a case of primary malignant lymphoma of the breast and present here the mammographic and ultrasonographic (US) findings with the pathology of this rare breast tumor. The patient was a 47-year-old woman with a left breast mass. Mammography showed a 3.0 x 1.5 cm, lobulated high-density mass with well-defined margins. US revealed a lobulated mass with fairly well-defined borders, hypoechoic and heterogenous internal echoes, and posterior acoustic enhancement. It was difficult to differentiate malignant lymphoma from breast carcinoma by imaging studies. This type of breast cancer should be added to a differential diagnosis when a solitary tumor is found in the breast on mammography.