Lymphoma of the breast is a rare diagnosis, accounting for less than 0.5% of all breast malignancies. Presentation is usually similar to that of breast cancer, with a painless palpable mass. This report describes a unique case of a 13 cm breast lymphoma. The patient is a 74 year old female who presented to clinic with a right breast mass that has been present since the 1970s. She had previously undergone multiple excisions of lesions on both breasts, always with benign pathology. In 2017, screening mammogram revealed a suspicious lesion in the right upper outer breast with associated axillary lymphadenopathy. She was lost to follow up but presented again after the mass significantly grew in size over several months. Mammography showed a large 13 x 8.7 cm lobulated mass. Biopsy of the lesion revealed diffuse large B-cell lymphoma. Treatment for this patient will begin with chemotherapy.
Keywords: breast; lymphoma; primary breast lymphoma.