Myeloid Sarcoma : Breast
The differential diagnosis of myeloid sarcoma of breast includes breast carcinomas, lymphoblastic lymphoma, diffuse large B-cell lymphoma, blastic plasmacytoid dendritic cell neoplasm, and extramedullary hematopoiesis (EMH). EMH may form a tumor-like breast mass in patients with primary myelofibrosis. It may be an incidental finding in breast carcinomas or benign breast lesions, or may be seen after neoadjuvant chemotherapy. The image shows a diffuse infiltrate of medium to large mononuclear cells with effacement of normal architecture. The tumor cells have scant to moderate amounts of cytoplasm, finely dispersed chromatin, and punctate nucleoli.