Multiple bilateral breast masses due to lymphoma metastases: A report of 2 cases highlighting the mammographic and sonographic features.

Metastases within breast usually occur due to a primary malignancy in the contralateral breast. Breast metastases from extra mammary malignancies are known to be very rare and the primary tumors are reported to be melanoma, lung cancer, gastro-intestinal primary tumors, neuroendocrine tumors, sarcomas, ovarian tumors and lymphomas. Breast lymphomas comprise 0.04%-0.7% of all cases of breast malignancies and may manifest either as a primary or a secondary variety. A primary breast lymphoma is known to be more infrequent than a secondary breast lymphoma. In patients with breast metastases the usual clinical presentation is with multiple palpable masses and imaging evaluation is the mainstay for initial diagnosis. We report the imaging features seen in 2 almost identical cases of secondary breast lymphoma. At mammography, multiple, round to elliptical, sharply circumscribed, high-density masses were seen, in which spiculation, calcification and architectural distortion were conspicuously absent. On sonography, these round /oval masses were homogenously hypoechoic, sharply circumscribed, showed a thin echogenic rim with posterior acoustic enhancement and were moderately to profusely vascular on color Doppler examination. These imaging features should suggest the possible diagnosis of metastases from a hematogenous malignancy and an ultrasound guided biopsy should be performed. Once the etiology of lymphoma is confirmed, a rigorous multi- modality imaging work up to identify the primary site, stage the disease and document other sites of dissemination is warranted.