Clinicopathological features of primary malignant lymphoma of breast

Objective To study the clinicopathological features,immunophenotypes and differential diagnosis of primary malignant lymphoma of breast. Methods The cilinical and pathological data of two cases were retrospectively analyzed, combined with immunohistochemistry. Results Two patients were all women,who presented with painless lumps in breast by accident were hospitalized. Histologically,tumor cells were uniform,both Indian- file arrangement,onion skin- like around the lobule or duct of mammary gland. Decrease of mammary lobules and ducts,and interstitial fibrous tissue proliferation were noted. The tumor cells were round, less cytoplasm, neat nuclear profile, and less mitosis. Immunohistochemically,tumor cells were positive for LCA,CD20,CD79a,and PCNA,but were negative for CK, vimentin,CD3,CD43,CD45RO,CD99,MPO,ER,PR,and CerbB-2,and Ki-67 index was all more than 30%. Follow-up data showed that one patient survived until now for 9 months,and another patient died after 43 months. Conclusion Primary malignant lymphoma of breast is a rare tumor and also has a poor prognoisis. Histologically,it should be distinguished from lobular carcinoma of breast,granulocytic sarcoma of breast,PNET and other small cells cancers.