Background: Breast lymphoma (BL) is a rare disease with increasing incidence. BL can be categorized as primary (PBL), when occurring solely in the breast, or secondary (SBL), when previously diagnosed extramammary lymphoma secondarily involves the breast. PBL and SBL are differentiated by the clinical context and by evaluating for multiplicity, bilaterality, and the presence of distant disease. Distinguishing between BL and breast carcinoma can be challenging both radiologically and pathologically. Nonspecific imaging features such as oval masses on mammography and hypoechoic or heterogeneous hypervascular masses on ultrasound may be present in both entities. Histopathologic analysis relying on hematoxylin-eosin staining alone can mimic that of invasive breast carcinoma; evaluation with flow cytometry, cytogenetic evaluation, and immunohistology staining is required to confirm diagnosis of BL. Misdiagnosis has severe consequences as the clinical treatments are vastly different for both entities. Surgery is the main treatment in the management of early-stage breast carcinoma, whereas lymphoma is treated with systemic therapy. To that end, the radiologist must first suspect BL to ensure that biopsy specimens are appropriately analyzed, and the correct diagnosis is achieved.
Learning Objectives: 1. Review the epidemiology and clinical presentation of PBL and SBL. 2. Recognize multimodality imaging and histopathology features of PBL and SBL through a case series from our institution. 3. Identify the similarities and differences between BL and breast carcinoma.
Abstract Content/Results: The first portion of the presentation will provide background education on PBL and SBL. The remainder of the presentation will be case-based, highlighting the spectrum of imaging features that can be seen with both PBL and SBL on mammography, ultrasound and MRI. Approximately 10 – 15 cases of BL will be presented, including a case occurring during pregnancy, a case of Burkitt transformation, and a case that involves a breast implant. An additional 3 – 5 comparison cases of breast carcinoma will also be presented.
Conclusion: Through this case series of biopsy-proven lymphoma and comparison cases of breast carcinoma, we hope to emphasize the variable imaging features of BL, the similarities between lymphoma and carcinoma, and the importance of including lymphoma on the differential of a malignant-appearing breast mass to ensure timely diagnosis and appropriate treatment.