Breast Lymphoma: Imaging Findings of 32 Tumors in 27 Patients

Abstract
To retrospectively evaluate the imaging findings of breast lymphomas in patients who had undergone mammography, ultrasonography (US), magnetic resonance (MR) imaging, or combined positron emission tomography (PET)/computed tomography (CT) scanning. The institutional review board approved this HIPAA-compliant study and waived informed consent. Twenty-seven women who had been diagnosed with breast lymphoma (32 tumors) and had undergone preoperative imaging were identified from the surgical pathology database (mean age, 51 years; median, 55 years; range, 19-78 years at time of diagnosis). Two radiologists reviewed the mammographic, US, and MR images. One nuclear medicine physician reviewed the PET/CT scans. All available pathologic specimens were reviewed by a hematologic pathologist. The mean tumor size at diagnosis was 2.9 cm (range, 1-5 cm). Seventeen tumors manifested with a palpable mass, two with diffuse enlargement of the breast, and 13 were asymptomatic. Twenty-two women underwent mammography; 24, US; one, MR imaging; and 10, PET/CT scanning. Mammograms of 25 tumors showed a noncalcified mass in 19, global asymmetry in four, focal asymmetry in one, and no abnormality in one. US of 29 tumors showed a mass in 26 and diffuse architectural distortion in three. Masses typically were irregular, hypoechoic, and hypervascular and demonstrated indistinct margins or an echogenic boundary. Dynamic contrast material-enhanced MR imaging of one tumor showed an intensely and heterogeneously enhancing mass with rapid enhancement and washout characteristics. PET/CT scans of 13 tumors showed intense diffuse hypermetabolism in 12 and response to therapy in all 12 tumors. The imaging findings reported in this study should alert the radiologist to a possible diagnosis of breast lymphoma.