Abstract
Background: Breast extramedullary myeloid sarcoma is a rare tumor that represents 0.12% of all acute myeloid leukemia cases. Diagnosis can be a real challenge due to the non-specific clinical and radiological features. Reported case: We report a case of a 25-year-old woman who had a painful breast lump. Breast ultrasound revealed an irregular bilateral suspicious mass, and the biopsy confirmed the diagnosis of breast granulocytic sarcoma (GS). The evolution was marked by a dorsal spinal cord compression. A chemotherapy was indicated but refused by the patient. The patient was finally treated with palliative radiotherapy, and chemotherapy. Conclusion: Breast myeloid sarcoma is a rare entity with symptoms reminiscent of those of primary breast cancer making its diagnosis so difficult. Treatment typically involves surgery, chemotherapy, and radiotherapy. Although the poor prognosis of breast GS, detecting the signaling pathways associated with myeloid cell migration to extra-medullary tissues may improve outcomes in the future.