Multidisciplinary Treatment of Post-radiation Sarcoma in the Left Axilla Following Radiotherapy for Breast Cancer: A Case Report and Review of the Literature.

Post-radiation sarcoma is a rare clinical entity, but it is considered an aggressive late complication of radiotherapy administered as adjuvant therapy for breast cancer treatment. Although radiotherapy significantly improves local disease control and survival, radiation-induced malignancies may occur years after treatment completion. Surgical resection with negative margins remains the cornerstone of management. However, treatment is often challenging because of prior irradiation, local tissue fibrosis, and advanced local disease. We report the case of a 65-year-old woman previously treated for breast cancer with breast-conserving surgery followed by adjuvant chemotherapy and radiotherapy. Twenty-three years after completion of radiotherapy, the patient developed a progressively enlarging mass within the irradiated field. Imaging studies revealed a heterogeneous soft tissue lesion involving the chest wall. Core needle biopsy demonstrated leiomyosarcoma. Following multidisciplinary team discussion, three weeks after the core biopsy, the patient underwent wide en bloc surgical resection with chest wall reconstruction. Histopathological examination of the surgical specimen revealed high-grade undifferentiated pleomorphic sarcoma with negative surgical margins (R0 resection). Postoperative recovery was uneventful. Then the patient received adjuvant chemotherapy and radiotherapy. The patient remains disease-free after three years of follow-up. Post-radiation sarcoma following breast cancer radiotherapy remains a rare and highly aggressive malignancy associated with poor prognosis. Early recognition and aggressive multidisciplinary treatment, particularly complete surgical excision with negative margins, are critical for improving outcomes.