Primary mammary (non-Hodgkin) lymphoma presenting as locally advanced breast cancer

Primary mammary lymphoma is a rare tumor that presents commonly as a large mass with no specific mammographic appearance and can be confused with poorly differentiated carcinoma on frozen section. With appropriate treatment, this breast malignancy has a relatively good prognosis. We report a case of primary mammary non-Hodgkin lymphoma in a 74-year-old woman that originally presented as locally advanced breast cancer with secondary inflammatory skin changes. Clinical findings, diagnostic work-up, and follow-up are provided along with a review of the literature on primary mammary lymphoma.