Bilateral primary lymphoma of the breast: a case report initially diagnosed by FNAC

Primary lymphoma of the breast (PLB) is a rare disease, representing 0.04-0.5% of all malignant breast neoplasms. We present a patient with bilateral breast involvement by a high-grade diffuse large B-cell lymphoma, which was diagnosed initially by fine-needle aspiration cytology (FNAC). Mammography revealed a diffuse increase in density of the right breast and a large solitary mass on the left breast, suggestive of an inflammatory carcinoma. The patient underwent FNAC and the diagnosis of a non-Hodgkin's lymphoma (NHL) was suggested. Physical examination revealed palpable bilateral axillary lymph nodes but no evidence of concurrent widespread disease. The patient underwent complete staging evaluation. The only positive findings were an elevated lactate dehydrogenase (LDH) and evidence of axillary lymphadenopathy on CT. Excisional biopsy was performed on the left breast. The morphological and immunohistochemical analysis confirmed the diagnosis of a high-grade diffuse large B-cell lymphoma with an immunophenotype suggestive of a germinal center cell origin.