BACKGROUND: Myeloid sarcoma is a rarely observed extramedullary presentation of myeloid leukemia that seldom manifests in the breast. Myeloid sarcoma can occur before, concurrently with, or following acute myeloid leukemia presentation. Few reports have focused on the imaging findings in cases of myeloid sarcoma of the breast, and the existing findings are variable and nonspecific; the present case report aimed to bridge this gap.

CASE REPORT: A 24-year-old female presented with a palpable lump at the upper outer quadrant of her right breast. She had noticed the mass 2 days prior to presentation. She was first diagnosed with acute myelogenous leukemia 18 months before the lump presentation and had undergone haploidentical stem cell transplantation 6 months prior. At the time of the breast lump presentation, she was undergoing chemotherapy for relapsed acute myeloid leukemia. Ultrasonography of her right breast revealed a circumscribed, oval mass corresponding to the palpable lump. Ultrasonography-guided 14-gauge core needle biopsy was performed on the breast mass, leading to a pathological diagnosis of myeloid sarcoma.

CONCLUSIONS: We reported a case of myeloid sarcoma involving the breast. On sonography, although the internal echotexture resembled that of breast hamartoma, the observed hard elasticity and high vascularity raised suspicions of malignancy.

Keywords: Breast, Elasticity Imaging Techniques, Leukemia, Myeloid, Acute, Sarcoma, Myeloid, Ultrasonography, Mammary, Breast Neoplasms, Image-Guided Biopsy, Stem Cell Transplantation, young adult