Abstract
Radiation-induced sarcoma (RIS) of the breast is a rare but serious late complication of radiotherapy, characterized by high-grade malignancy, rapid recurrence, and poor prognosis. Although rare, its incidence may increase due to improved survival rates among breast cancer patients. We report the case of a 56-year-old woman who developed a pleomorphic undifferentiated sarcoma in the irradiated field seven years after adjuvant radiotherapy for breast cancer. This case highlights the diagnostic challenges, therapeutic considerations, and prognostic implications of this rare entity.