This document presents a case report of a 40-year-old woman who presented with a rapidly enlarging swelling in her right breast over the past 4 months, which had reached approximately 10cm in size. She also reported a smaller swelling in her right axilla for the past 2 months. More recently, she developed an ulcer on her right breast above the swelling associated with serous discharge and pain. On examination, asymmetry was noted between breasts with the right breast higher than the left. An ulcer was seen on the right breast involving the nipple with serous discharge. Differential diagnoses included phylloides sarcoma, plasma cell mastitis, tuberculosis of the breast, and chronic fat necrosis.