Primary Granulocytic Sarcoma Presenting as Bilateral Breast Masses

Primary granulocytic sarcoma (GS) of the breast is rare. The sonographic finding of GS is nonspecific, mainly noncalcified hypoechoic lesion with ill-defined margin and hypervascularity. Correct diagnosis is important to avoid unnecessary surgery. However, distinguishing GS from metastatic malignancies or other hematologic malignancies is difficult if there is a lack of clinical information of known hematologic disorders in the patient. We describe a 51-year-old woman who initially presented with bilateral breast masses in whom histologic study revealed a pattern of GS. She was finally diagnosed to have acute myelogenous leukemia.