Abstract
Myeloid sarcoma is a rare, solid extramedullary tumor originating from immature granulocytic cells or monocytes. Breast involvement without an aleukemic or myeloproliferative disorder is very infrequent. A 21-year-old female patient was admitted with bilateral palpable breast masses for four months. The patient had given birth approximately one year ago. The ultrasonographic examination revealed multiple, oval shaped-some of them with microlubulated margins-hypoechoic, solid masses of which, the largest mass measured 4.5 × 2.5 cm, evaluated as BI-RADS 4. The histopthological examination suggested hematolymphoid neoplasm. In the differential diagnosis of solid breast lesions, myeloid sarcoma should be kept in mind even without hematological findings. Early diagnosis of this tumor is important for the effectiveness of the medical treatment.