Primary non-Hodgkin's lymphoma of the breast: a case report.

UNLABELLED Extranodal non-Hodgkin's lymphoma (NHL) of the breast is a rare entity. It represents 0.04-1.1% of malignant tumors of the breast. 1.7-2.2% of extranodal lymphomas and 0.7% of all NHL. However, primary NHL (PNHL) is the most frequent hematopojetic tumor of the breast. CASE A 23-year-old woman presented with a mass in the left breast for 3 months followed by enlarged left axillary lymph nodes. Mammography showed a diffuse increase in the density of the left breast. Other investigations were unremarkable. Both fine needle aspiration cytology (FNAC) and histopathology were diagnostic of NHL. Immunohistochemistry was confirmatory of NHL, diffuse large cell type, of B-cell lineage. CONCLUSION Primary and secondary lymphomas of the breast, though rare, should be considered in the differential diagnosis of breast malignancies. PNHL of the breast is usually right sided, but this patient had left breast involvement. Diagnosis by FNAC was successful as the cytologic picture is similar to that of any other lymphoid or extranodal NHL. When histopathology and immunohistopathology are conclusive, FNAC, supplemented by immunocytochemistry, can be applied as a simple, reliable and cost-effective tool in the early diagnosis of breast lymphomas.